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Recent Canonical Ubuntu Linux Security Advisories

Advisory Title Published
USN-8911-1 USN-8911-1: Linux kernel (OEM) vulnerabilities October 9, 2026
USN-8887-3 USN-8887-3: Linux kernel vulnerabilities October 9, 2026
USN-8875-2 USN-8875-2: Linux kernel (NVIDIA) vulnerabilities October 9, 2026
USN-8903-2 USN-8903-2: Linux kernel vulnerabilities October 9, 2026
USN-8905-2 USN-8905-2: Linux kernel (GCP) vulnerabilities October 9, 2026
USN-8908-1 USN-8908-1: BlueZ vulnerabilities October 8, 2026
USN-8910-1 USN-8910-1: libxml2 vulnerabilities October 8, 2026
USN-8909-1 USN-8909-1: libde265 vulnerability October 8, 2026
USN-8907-1 USN-8907-1: libgit2 vulnerability October 8, 2026
USN-8902-1 USN-8902-1: libarchive vulnerability October 8, 2026

By the Year

In 2026 there have been 5440 vulnerabilities in Canonical Ubuntu Linux with an average score of 7.7 out of ten. Last year, in 2025 Ubuntu Linux had 2930 security vulnerabilities published. That is, 2510 more vulnerabilities have already been reported in 2026 as compared to last year. However, the average CVE base score of the vulnerabilities in 2026 is greater by 0.41.




Year Vulnerabilities Average Score
2026 5440 7.66
2025 2930 7.25
2024 3597 6.96
2023 1082 6.85
2022 1211 6.98
2021 752 6.84
2020 754 6.21
2019 796 6.95
2018 932 7.10

It may take a day or so for new Ubuntu Linux vulnerabilities to show up in the stats or in the list of recent security vulnerabilities. Additionally vulnerabilities may be tagged under a different product or component name.

Recent Canonical Ubuntu Linux Security Vulnerabilities

NTFS-3G <2026.7.7: OOB Read in ntfs_fix_file_name() via readlink
CVE-2026-46571 5.5 - Medium - October 07, 2026

In NTFS-3G before 2026.7.7, a out-of-bounds read exists in ntfs_fix_file_name() in libntfs-3g/reparse.c that allows an attacker to read possibly confidential information in ntfs-3g process memory by crafting a malicious NTFS image. The out-of-bounds read is triggered by a readlink on a corrupted file.

Out-of-bounds Read

NTFS-3G <2026.7.7 heap BOF in ntfs_ib_cut_tail() libntfs-3g/index.c
CVE-2026-46572 7.4 - High - October 07, 2026

In NTFS-3G before 2026.7.7, a heap buffer overflow exists in ntfs_ib_cut_tail() in libntfs-3g/index.c that allows an attacker to corrupt heap memory in the SUID-root ntfs-3g binary by crafting a malicious NTFS image. The overflow is triggered by creating a file in a specially crafted directory.

Heap-based Buffer Overflow

Heap Overflow in ntfs-3g before 2026.7.7 (ntfs_index_walk_down) via SUID root
CVE-2026-46570 8.1 - High - October 07, 2026

In NTFS-3G before 2026.7.7, a heap buffer overflow exists in ntfs_index_walk_down() in libntfs-3g/index.c that allows an attacker to corrupt heap memory in the SUID-root ntfs-3g binary by crafting a malicious NTFS image. The overflow is triggered by reading the special crafted file metadata.

Heap-based Buffer Overflow

NTFS-3G <2026.7.7 Heap Buffer Overflow in ntfs_ib_copy_tail()
CVE-2026-46569 7.7 - High - October 07, 2026

In NTFS-3G before 2026.7.7, a heap buffer overflow exists in ntfs_ib_copy_tail(), in libntfs-3g/index.c, that allows an attacker to corrupt heap memory in the SUID-root ntfs-3g binary by crafting a malicious NTFS image. The overflow is triggered by extending a directory, e.g., by creating a file.

Heap-based Buffer Overflow

NTFS-3G <=2026.7.7 Heap Buffer Overflow in ntfscat
CVE-2026-42616 - October 07, 2026

In NTFS-3G before 2026.7.7, a heap buffer overflow exists in cat() in ntfscat.c that allows an attacker to corrupt heap memory in the ntfscat binary by crafting a malicious NTFS image. The overflow is triggered by reading a file.

NTFS-3G <2026.7.7 heap ble in ntfs_ir_to_ib() SUID binary
CVE-2026-42617 7.1 - High - October 07, 2026

In NTFS-3G before 2026.7.7, a heap buffer overflow exists in ntfs_ir_to_ib() in index.c that allows an attacker to corrupt heap memory in the SUID-root ntfs-3g binary by crafting a malicious NTFS image. The overflow is triggered by extending a directory, e.g., by creating a file.

Heap-based Buffer Overflow

NTFS-3G<2026.7.7 Heap Buffer Overflow in ntfs_decompress()
CVE-2026-42618 7.1 - High - October 07, 2026

In NTFS-3G before 2026.7.7, a heap buffer overflow exists in ntfs_decompress() in compress.c that allows an attacker to corrupt one byte of heap memory in the SUID-root ntfs-3g binary by crafting a malicious NTFS image. The overflow is triggered by reading the special crafted file.

Heap-based Buffer Overflow

U-Boot <2026.10-rc3 IP_DEFRAG OOBW in __net_defragment()
CVE-2026-71971 8.8 - High - September 29, 2026

U-Boot before 2026.10-rc3 with CONFIG_IP_DEFRAG enabled contains an out-of-bounds write vulnerability in the __net_defragment() function in net/net.c. Remote attackers can send a crafted IP fragment with non-zero offset and More-Fragments flag set during netboot to corrupt adjacent memory and crash the bootloader.

Memory Corruption

OpenSSL QUIC stack no CID limit check 400MB memory exhaustion
CVE-2026-84784 7.5 - High - September 29, 2026

Issue summary: A malicious remote peer may flood the local QUIC stack with NEW_CONNECTION_ID frames by avoiding a limit check on how many connection IDs the remote QUIC stack can use. Impact summary: The local QUIC stack sends a RETIRE_CONN_ID frame for every NEW_CONNECTION_ID frame it receives. The RETIRE_CONN_ID frame is dispatched via the Control Frame Queue (CFQ). If the remote peer also withholds ACKs, then it can force the local stack to allocate ~400MB (depending on ACK delay). CWE: CWE-770: Allocation of Resources Without Limits or Throttling Description: RFC 9000 sections 5.1.1 and 5.1.2 [1] describe the mechanism by which a remote peer can notify the local QUIC stack to change the destination connection ID (a.k.a. CID) the local stack uses to identify the connection at the remote peer. Each CID is associated with a sequence number. The sequence number is transmitted in NEW_CONNECTION_ID and RETIRE_CONNECTION_ID frames to identify the CID which is being either associated with a connection or retired. The remote peer sends a NEW_CONNECTION_ID frame to let the local stack know a new CID is being associated with an existing connection. The NEW_CONNECTION_ID frame carries the new CID, its sequence number, and the retire-prior-to number. The retire-prior-to identifies existing CIDs that are to be retired. The local QUIC stack must send a RETIRE_CONNECTION_ID for every destination CID whose sequence number is less than retire-prior-to. The CID becomes retired after the local stack receives an ACK for its RETIRE_CONNECTION_ID frame. Although the OpenSSL QUIC stack supports at most one destination CID for every connection, it can be tricked into processing more than one RETIRE_CONNECTION_ID frame per connection. The OpenSSL QUIC stack currently retires the destination CID as soon as it receives the NEW_CONNECTION_ID, while in fact the destination CID must be retired after an ACK for the RETIRE_CONNECTION_ID frame is received. Correcting the flawed logic also fixes the backlog growth. [1] https://datatracker.ietf.org/doc/html/rfc9000#name-issuing-connection-ids FIPS impact: no The FIPS module is not affected as the QUIC implementation is outside of the OpenSSL FIPS module boundary.

Allocation of Resources Without Limits or Throttling

OpenSSL DTLS Out-of-Bounds Read via Suspended Write Retransmission
CVE-2026-84782 8.2 - High - September 29, 2026

Issue summary: The DTLS retransmission logic does not correctly handle a handshake message write that is suspended part-way through. The retransmitted message can be read past the message buffer and the retransmission overwrites the internal state the suspended write needs to resume correctly. Impact summary: The retransmitted message can disclose a heap memory to the peer as plaintext handshake data or cause a crash and a Denial of Service when the read reaches an unmapped memory region. CWE: CWE-125: Out-of-bounds Read Description: DTLS handshake messages can be written out in multiple fragments, and a write can suspend mid-message (returning WANT_WRITE) if the underlying transport temporarily cannot accept more data. While such a write is suspended, the DTLS retransmission timer may independently fire and ask the retransmission logic to resend an earlier, already-acknowledged-as-sent message from its retransmit queue. The retransmission logic reused the same internal buffer and position tracking as the message that was still being written, without resetting the position back to the start of the message being retransmitted. As a result the retransmission was read starting from wherever the suspended write had left off, producing a mislabelled message whose body was leftover bytes from the other, larger message still in flight - content that was never meant to be sent at that point, and which could run past the end of the allocated buffer. Separately, even when the retransmission is positioned correctly, allowing it to run to completion while another write is suspended overwrites the same shared bookkeeping that the suspended write depends on to resume. When the application later resumes the suspended write (via a subsequent SSL_read(), SSL_write(), SSL_accept(), or SSL_connect() call), it finds that bookkeeping in a state inconsistent with the message and aborts the process in a debugging build. The fix resets the retransmission's read position to the start of the message before resending, and skips retransmission entirely whenever a handshake write is still suspended, deferring to the next call that resumes it instead. FIPS impact: no The affected code is outside the FIPS module boundary.

Out-of-bounds Read

OpenSSL SM2 Signing Timing Side-Channel via Non-Constant Time Arithmetic
CVE-2026-77696 3.7 - Low - September 29, 2026

Issue summary: SM2 signature generation uses non-constant-time arithmetic on secret values, forming a timing side-channel. Impact summary: An attacker able to measure SM2 signing times may learn information about the per-signature secret nonce, which over many signatures can, via a lattice / Hidden Number Problem attack, lead to recovery of the private key. CWE: CWE-208: Observable Timing Discrepancy Description: SM2 signature generation computes the signature value using variable-time BIGNUM operations on the secret nonce and the private key, so the time taken to produce an SM2 signature depends on these secret values, forming a timing side-channel. Applications performing SM2 signature generation are affected on all platforms. FIPS Impact: no SM2 is not a FIPS algorithm.

Observable Timing Discrepancy

OpenSSL DTLS 1.2 AEAD CVE-2026-75806: Short Record DoS
CVE-2026-75806 5.3 - Medium - September 29, 2026

Issue summary: An established DTLS 1.2 association using an AEAD cipher suite can be terminated by a single unauthenticated datagram whose encrypted fragment is shorter than the mandatory explicit IV and authentication tag overhead. Impact summary: An attacker who can send a datagram that is routed to an existing DTLS 1.2 association can tear that association down without knowing any key material. This is a Denial of Service limited to the targeted association. There is no memory safety or confidentiality impact. CWE: CWE-1284: Improper Validation of Specified Quantity in Input Description: In TLS 1.2 and DTLS 1.2 every record protected by an AEAD cipher suite carries an explicit IV followed by the ciphertext and an authentication tag. When decrypting such a record the record layer passed the record length to the cipher implementation before checking that the record was long enough to contain the explicit IV and the tag. For a record shorter than that overhead the cipher implementation rejected the impossible length, and the record layer treated this as an internal failure and raised a fatal internal_error alert instead of treating the record as one that failed authentication. In TLS 1.2 the same record causes a fatal internal_error alert instead of the expected bad_record_mac alert. Since any undecryptable record already terminates a TLS connection, this is a protocol conformance issue rather than a security issue in TLS. The fix validates the record length against the explicit IV and tag length before any AEAD processing, so that TLS reports bad_record_mac and DTLS silently discards the record. FIPS impact: no The affected code is outside the FIPS module boundary.

Improper Validation of Specified Quantity in Input

OpenSSL CMP Client NULLPointer Deref via Crafted Revocation Response
CVE-2026-75805 5.3 - Medium - September 29, 2026

Issue summary: A CMP client that requests certificate revocation on the basis of a PKCS#10 CSR may dereference a NULL pointer and terminate abnormally when processing a crafted revocation response. Impact summary: The NULL pointer dereference happens on a read which leads to a crash and a Denial of Service for the affected client application. CWE: CWE-476: NULL-pointer dereference Description: A CMP client revoking a certificate has to tell the server which certificate to revoke, and may do so by supplying a PKCS#10 CSR instead of the certificate itself or its issuer name and serial number. This is 'openssl cmp -cmd rr -csr <file>' on the command line, or OSSL_CMP_exec_RR_ses() with the certificate supplied via OSSL_CMP_CTX_set1_p10CSR() through the API. A CSR does not contain the issuer name and serial number of the certificate, so the client does not send them. A server may optionally name the certificate it revoked in its response, and the client then compares that name against what it sent. Having sent neither an issuer name nor a serial number, it has nothing to compare against, and a server returning a specially crafted name causes the client to read from a NULL pointer and crash. The revocation response is checked for valid message protection before the affected code is reached, so an attacker must be a malicious or compromised CMP server, or a man-in-the-middle in possession of the secret used for message protection. Clients that identify the certificate to be revoked by a certificate or by issuer and serial number rather than by a PKCS#10 CSR are not affected. FIPS impact: no No FIPS modules are affected by this issue, as the CMP protocol implementation is outside the OpenSSL FIPS module boundary.

NULL Pointer Dereference

OPENSSL QUIC FC Bypass: 100MB Heap
CVE-2026-75804 5.3 - Medium - September 29, 2026

Issue summary: OpenSSL QUIC stack does not enforce connection level flow control for streams. Remote peers may send more bytes as long as they fit within the stream flow control limits. Impact summary: A malicious remote peer may exploit the lack of connection flow control for streams to make the QUIC stack receive ~100MB of memory instead of 768 KiB (default flow control window size). CWE: CWE-770: Allocation of Resources Without Limits or Throttling Description: The local QUIC stack advertises two flow control limits to its remote peer: stream flow control limit and connection flow control limit. The remote peer must follow both limits when transmitting stream data. Whenever the local QUIC stack receives a stream frame, it validates that the size of the received stream frame stays within flow control limits. If either limit is exceeded (stream level or connection level), then the QUIC stack must close the connection with a flow control error. The vulnerable OpenSSL QUIC stack enforces the stream-level but not the connection-level limit. To exploit the issue, three conditions must be met: - the remote peer opens several streams - each stream must stay within the stream-level flow control limit - there must be no zero-offset byte sent on any of the streams (to prevent the vulnerable QUIC stack from consuming data). By meeting the conditions above, the remote peer may make the local stack allocate 2 x MAX_STREAMS x (stream flow control limit) bytes of memory. MAX_STREAMS defaults to 100, and the limit applies to both bidirectional and unidirectional streams, making it 200 in total. The default flow control window for a stream is 512kB. The remote peer may force the vulnerable QUIC stack to allocate 100MB of heap per connection. FIPS impact: no The FIPS module is not affected as the QUIC implementation is outside of the OpenSSL FIPS module boundary.

Allocation of Resources Without Limits or Throttling

OpenSSL SSL_set_SSL_CTX TLS Context OOB Read/Write (4.0+)
CVE-2026-72897 7.5 - High - September 29, 2026

Issue summary: A TLS server that calls SSL_set_SSL_CTX() to switch a connection to a different SSL_CTX part way through a handshake may access memory beyond the end of an internal array if the replacement context knows about more provider signature algorithms than the context the connection was created from. Applications which never call SSL_set_SSL_CTX() are not affected. Impact summary: A remote peer may be able to cause a small out-of-bounds read, and in some circumstances a fixed-value out-of-bounds write, on the server heap. This may lead to a Denial of Service. CWE: CWE-787: Out-of-bounds Write Description: A TLS connection records how many certificate slots it has when it is created, taken from the SSL_CTX that created it: the built-in certificate types plus one slot for each provider TLS-SIGALG entry that context was aware of. That count sizes an internal array of per-slot certificate validity flags. An application may replace a connection's SSL_CTX part way through the handshake by calling SSL_set_SSL_CTX(), most commonly from a servername callback in order to serve a different virtual host. Doing so did not refresh the recorded count. A provider signature algorithm's slot index is its position in the list of whichever context resolves it, so if the replacement context is aware of more of them than the original, an algorithm offered by the peer can resolve to an index beyond the end of the array. Processing the peer's signature algorithms then reads one four byte word past the end for each such algorithm and, where the word read is zero, writes a fixed value over it. A peer offering many of them can corrupt heap metadata and abort the process. Only provider signature algorithms which occupy one of the excess slots, and which the server also has configured, have this effect. Codepoints the replacement context does not recognise are discarded without being resolved to a slot, and provider signature algorithms are usable only from TLS 1.3. The two contexts must therefore be aware of different numbers of provider signature algorithms, which requires separate library contexts, a provider loaded between the two being created, or providers which differ in what they advertise - in 4.0, for example, the default provider advertises SM2 where the FIPS provider does not. A deployment meeting the condition is also unable to negotiate the affected algorithms with legitimate clients, since the same stale count hides the corresponding certificates, so the misconfiguration is likely to be noticed. For that reason, and because the configuration is not the default, this issue has been assessed as Low severity. FIPS impact: no No FIPS modules are affected by this issue as the affected code is outside the OpenSSL FIPS module boundary.

Memory Corruption

OpenSSL SM2 Scalar Mult. Timing Leak on ARM64/RISC-V (4.0.0)
CVE-2026-54875 3.7 - Low - September 29, 2026

Issue summary: A non-constant-time optimized implementation of scalar point multiplication is used for SM2 private key operations on ARM64 and RISC-V platforms. Impact summary: An attacker able to measure the time taken by, or to observe the cache-line access pattern of SM2 signing or decryption on an affected platform can learn information about the secret scalar. CWE: CWE-208: Observable Timing Discrepancy Description: On ARM64 and RISC-V processors, the SM2 curve uses an optimized scalar multiplication implementation whose conditional branches and table look ups are chosen according to the bits of the secret scalar. The execution time and the cache-access pattern therefore depend on the long-term private key (during SM2 decryption) or the per-signature nonce (during SM2 signature generation), forming a timing and cache side-channel. FIPS Impact: no SM2 is not a FIPS algorithm and the optimized SM2 implementation is not part of the FIPS module. OpenSSL 4.0, 3.6, 3.5 and 3.4 are vulnerable to this issue on AArch64 and RISC-V. OpenSSL 3.0, 1.1.1 and 1.0.2 are not affected by this issue. OpenSSL 4.0 users should upgrade to OpenSSL 4.0.3. OpenSSL 3.6 users should upgrade to OpenSSL 3.6.5. OpenSSL 3.5 users should upgrade to OpenSSL 3.5.9. OpenSSL 3.4 users should upgrade to OpenSSL 3.4.8. This issue was reported on 2 May 2026 by Abhinav Agarwal. It was independently reported on 6 June 2026 by Feng Xue. The fix was developed by Igor Ustinov. -- cut (non-publishing metadata for internal use) -- Reported by: Abhinav Agarwal, Feng Xue Fixed by: Igor Ustinov

Observable Timing Discrepancy

OpenSSL QUIC Stack Memory Overcommit via Long-Lived Buffers
CVE-2026-54873 7.5 - High - September 29, 2026

Issue summary: QUIC process may keep memory for QUIC packet buffer for much longer period than necessary. Impact summary: Remote peer can exploit this vulnerability by sending maliciously crafted packets, making the local QUIC stack to keep the memory for packet buffers allocated. The time for which the memory remains allocated is entirely under the control of the potentially malicious remote peer. CWE: CWE-770: Allocation of Resources Without Limits or Throttling Description: To save copy operation from the packet buffer to the stream reassemble buffer the QUIC stack leaves the stream data on the packet buffer waiting to be copied to a buffer provided by the local receiving application. The QUIC stack releases a reference to the packet buffer only after the data are copied to the application buffer. This design is more efficient for legitimate data transfers but enables an attacker to allocate a lot more memory than actually required by the data kept in the receiving stream buffer. To mitigate the vulnerability, the QUIC stack now calculates and monitors memory overhead for every stream. The memory overhead for a single stream frame is calculated as a difference between the size of the whole packet that carries the stream frame and the size of the stream frame itself. The memory overhead for a single stream frame is added to the total (cumulative) memory overhead QUIC stack keeps for each stream. Once the cumulative memory overhead exceeds 64kB, the QUIC stack moves the stream frame data from the packet buffer to the stream buffer, starting with the next packet received. FIPS impact: no The FIPS module is not affected as the QUIC implementation is outside of the OpenSSL FIPS module boundary.

Allocation of Resources Without Limits or Throttling

OpenSSL: Generic EC Scalar Mul Timing Leak Exposes ECDSA/SM2 Nonce
CVE-2026-54872 3.7 - Low - September 29, 2026

Issue summary: The generic elliptic-curve scalar multiplication used for ECDSA and SM2 signature operations with curves that do not have a dedicated implementation leaks information about the secret nonce through timing. Impact summary: An attacker able to measure signing times may learn information about the per-signature secret nonce, which over many signatures can, via a lattice / Hidden Number Problem attack, lead to recovery of the private key. CWE: CWE-208: Observable Timing Discrepancy Description: The generic elliptic-curve scalar multiplication used for curves that do not have a dedicated constant-time implementation pads the secret scalar with non-constant-time BIGNUM operations, so the time taken depends on the value of the secret scalar derived from the ECDSA and SM2 nonce. The leak is very small; observing it requires a large number of measurements. The effect is largest for curves whose group order lies on a machine-word boundary, such as brainpoolP384r1. Applications using ECDSA signing over the Brainpool and other generic prime curves, and SM2 signing on platforms that use the generic implementation, are vulnerable to this issue. The NIST curves P-256, P-384 and P-521 use dedicated constant-time implementations and are not affected. FIPS Impact: no The FIPS modules are not affected: the approved NIST curves used in the FIPS provider have dedicated constant-time implementations and do not use the affected code path.

Observable Timing Discrepancy

OpenSSL QUIC: Stream Reassembly O(n^2) CPU DoS via Out-of-Order Frames
CVE-2026-42772 5.3 - Medium - September 29, 2026

Issue summary: The QUIC stream reassembly algorithm performance deteriorates progressively as packets are arriving out of order. The worst case has a quadratic complexity proportional to the number of stream frames kept in the buffer for the received stream data. Impact summary: A remote QUIC peer that completes the handshake can create a connection-scoped CPU pressure and potentially a Denial of Service using compliant STREAM frames inside the advertised receive window, with low attacker bandwidth. CWE: CWE-407: Inefficient Algorithmic Complexity Description: OpenSSL manages received QUIC stream fragments using a doubly-linked list. While it optimizes for append operations (at the end of the list), it falls back to a head-to-tail linear search for any fragment that does not immediately follow the current `tail`. By manipulating the sequence of offsets, an attacker can force the server to perform O(n^2) operations, consuming excessive CPU time for the QUIC process. FIPS impact: no The FIPS module is not affected as the QUIC implementation is outside of the OpenSSL FIPS module boundary.

Inefficient Algorithmic Complexity

OpenSSL QUIC Server Amplification via Unvalidated Credit Computation
CVE-2026-35191 3.7 - Low - September 29, 2026

Issue summary: The OpenSSL QUIC server, when configured to not preform address validation, can be forced to count incoming packets multiple times in its unvalidated credit computation, leading to a violation of the RFC 9000 unvalidated connection amplification limit of 3 times the amount of data received. Impact summary: A remote attacker able to spoof packets to a server using the OpenSSL QUIC implementation might use the server for an amplification of a DDoS attack. CWE: CWE-440: Expected Behavior Violation Description: OpenSSL's QUIC stack, when operating as a server, enforces client address validation (RFC 9000, Section 8), to confirm the peer address is not used for a traffic amplification attack. If this feature is disabled on the server, the QUIC stack limits the amount of server data that can be sent to 3 times the amount of data received from the peer address, until such time as the TLS handshake is completed. The OpenSSL QUIC server, when operating in non-validation mode, adds the length of the whole datagram received to the unvalidated credit limit when processing each QUIC packet in the datagram. A remote peer may, after establishing a connection with an initial client hello frame, send a subsequent datagram containing multiple QUIC packets, leading the server to account the entire datagram length for each packet in the datagram, resulting in the server believing that the peer has sent more data than it actually has, thereby violating the 3x amplification limit mandated by the RFC. FIPS impact: no As the QUIC stack lives outside the FIPS module boundary, no FIPS modules are affected by this CVE.

Expected Behavior Violation

OpenSSL CRL DP Heap DoS via nameRelativeToCRLIssuer
CVE-2026-35189 5.3 - Medium - September 29, 2026

Issue summary: A certificate with many nameRelativeToCRLIssuer CRL distribution points causes disproportionate heap growth when OpenSSL caches X.509 extensions. Impact summary: Receiving a crafted certificate from a malicious peer can lead to significant memory pressure and possible Denial of Service in clients or in servers that solicit client certificates. CWE: CWE-770: Allocation of Resources Without Limits or Throttling Description: A certificate or a set of certificates that fits under the limit for size of certificates accepted from the peer (~100 KiB) can result in allocation of several hundred MiB of resident memory on the receiving side during a normal TLS handshake. This may be enough to crash the client or server, if multiple concurrent connections lead to similarly large memory allocations. The fix postpones processing of the CRL distribution points extensions in certificates to the time when the processed value is required for CRL processing. This avoids keeping large memory allocations for a long time when such certificates are received. FIPS impact: no The affected code is outside the FIPS module boundary.

Allocation of Resources Without Limits or Throttling

Das U-Boot IP Reassembly State Leak Arbitrary Code via IP Fragments
CVE-2026-15390 9 - Critical - September 29, 2026

Das U-Boot with CONFIG_IP_DEFRAG=y parameter fails to clear IP reassembly state after delivering a complete datagram. An attacker who can deliver fragmented IP traffic can execute arbitrary code by sending duplicated last-fragment IP packets. This issue was fixed in commit b1aec609bb5e0d08c25c888c91935287ab4ee5fa in version 2026.07.

Memory Corruption

Linux Kernel: Thunderbolt XDomain Ref Leak During Service Release
CVE-2026-97509 8.8 - High - September 24, 2026

In the Linux kernel, the following vulnerability has been resolved: thunderbolt: Keep XDomain reference during the lifetime of a service This is needed because we release the service ID in tb_service_release() and the ID array is owned by the parent XDomain.

LibreOffice 26.2/26.2.5 PICT Image Import OOB Read via Palette Index
CVE-2026-63279 5.4 - Medium - September 22, 2026

LibreOffice can import PICT images, which may be embedded in documents. An out of bounds read existed when importing an image that uses a colour palette. The palette index held in the image data was used without being checked against the number of entries the palette has, so an index past the last entry read memory outside the palette. In fixed versions the palette index is limited to the entries present.

Out-of-bounds Read

LibreOffice 26.2<26.2.5 URL EnvVar Expansion Exfil
CVE-2026-63278 6.7 - Medium - September 22, 2026

URLs could be constructed which expanded environment variable or INI file values, so potentially sensitive information could be exfiltrated to a remote server on opening a document containing such links. The check added for CVE-2024-12426 did not recognise every way of naming the package content provider, so a URL that named it differently still reached the expansion. In fixed versions the package content provider is matched when the URL is checked.

Information Disclosure

LibreOffice 26.2.x Stack Buffer Overflow in CFF to Type1 Font Conversion
CVE-2026-63276 5.4 - Medium - September 22, 2026

LibreOffice converts CFF fonts to Type 1 when it subsets a font, which happens when a document is exported to PDF, and CFF fonts may be embedded in documents. A stack buffer overflow existed in that conversion. The converted operators were written into a fixed size buffer with no check that they still fit, so a glyph emitting many operators wrote past the end of the buffer. In fixed versions the remaining capacity is tracked and the conversion stops when it is used up.

Memory Corruption

LibreOffice 26.2 Stack Buffer Overflow in CFF Font Hint Parsing
CVE-2026-63275 5.4 - Medium - September 22, 2026

LibreOffice can read CFF fonts, which may be embedded in documents. A stack buffer overflow existed when reading the hints of a glyph. The number of hints was checked against the wrong bound, so a glyph declaring more hints than the array can hold wrote past its end. In fixed versions the hint count is checked against the capacity the array really has.

Memory Corruption

LibreOffice Draw PDF heap overflow <26.2.5
CVE-2026-63274 5.4 - Medium - September 22, 2026

LibreOffice Draw can import PDF documents. A heap buffer overflow existed when importing a stream object. The length of the stream was taken from the object's own dictionary and was not checked against the number of bytes actually present, so copying the stream read and wrote past the end of the buffer holding it. In fixed versions the declared length is clamped to the bytes actually read.

Memory Corruption

LibreOffice 26.2 Heap Buffer Overflow in PDF Import (before 26.2.5)
CVE-2026-63273 5.4 - Medium - September 22, 2026

LibreOffice Draw can import PDF documents. A heap buffer overflow existed when importing an encrypted document. The length of the decryption key was taken from the document's own encryption dictionary and was used to fill a fixed size key buffer without being checked against it, so a length larger than that buffer wrote past its end. In fixed versions a declared key length larger than the buffer is rejected.

Memory Corruption

LibreOffice 26.2.4 WMF Import Heap Buffer Overflow
CVE-2026-63272 5.4 - Medium - September 22, 2026

LibreOffice can import WMF graphics, which may be embedded in documents. A heap buffer overflow existed when importing a text record that carries its own character advance widths. The count of advance values and the length of the text were read separately from the file and were not required to agree, so drawing the text walked the advance array by character position and ran past its end when the array was the shorter of the two. In fixed versions an advance array shorter than its text is ignored.

Memory Corruption

OpenStack Octavia <18.0.1 Amphora TLS Cipher Injection (HAProxy Config)
CVE-2026-94572 9.4 - Critical - September 21, 2026

In OpenStack Octavia before 18.0.1, the Amphora provider driver did not validate the listener and pool tls_ciphers field for control characters. The value is written verbatim into the HAProxy configuration generated on the amphora, and thus an authenticated project member who owns a TLS-enabled load balancer can embed a newline and inject arbitrary HAProxy configuration directives. Only deployments using the Amphora provider are affected.

Code Injection

OpenStack Octavia <18.0.1 L7 Policy Redirect URL Control char Injection
CVE-2026-94571 9.4 - Critical - September 21, 2026

In OpenStack Octavia before 18.0.1, the Amphora provider driver did not reject control characters in the L7 policy redirect_url and redirect_prefix fields. The RFC 3986 URL validator percent-encodes control characters before validating, and thus newlines passed structural checks, but Octavia stored and wrote the raw unencoded value directly into the HAProxy configuration generated on the amphora. An authenticated project member who owns a load balancer can therefore inject arbitrary HAProxy directives through a REDIRECT_TO_URL L7 policy. Only deployments using the Amphora provider are affected.

Code Injection

FluidSynth OOB via synth.midi-channels ( <2.5.6)
CVE-2026-61714 7.8 - High - September 18, 2026

FluidSynth is a software synthesizer based on the SoundFont 2 specifications. From 2.2.4 until 2.5.6, configuring synth.midi-channels above 16 allows the MIDI player to index _fluid_player_t::channel_isplaying outside its fixed-size heap allocation while tracking active channels. The resulting out-of-bounds reads and writes invoke undefined behavior and may compromise confidentiality, integrity, or availability. No crafted MIDI file is required because the unsafe condition is created by the channel-count configuration itself. Keeping synth.midi-channels at its default value of 16 avoids the vulnerable path. This issue is fixed in version 2.5.6.

Heap-based Buffer Overflow

Out-of-bounds Heap Write in FluidSynth 1.1.2-2.5.6 via pitch_bend_range
CVE-2026-58264 9.8 - Critical - September 18, 2026

FluidSynth is a software synthesizer based on the SoundFont 2 specifications. From 1.1.2 until 2.5.6, the FluidSynth command handler accepts a pitch_bend_range command whose channel argument is not bounds checked before the supplied value is written through the selected synth channel. An out-of-range channel can therefore cause an out-of-bounds heap write, leading to denial of service or possible code execution. The issue is remotely reachable when the TCP server is enabled through new_fluid_server() or fluidsynth -s, and it is locally reachable through malicious commands delivered to the FluidSynth shell on standard input. Applications that do not use the shell, command handler, or TCP server are not affected. This issue is fixed in version 2.5.6.

Heap-based Buffer Overflow

Rsyslog mmpstrucdata Stack Overflow (8.2606.0)
CVE-2026-61548 8.1 - High - September 18, 2026

Rsyslog is a rocket-fast system for log processing. From 7.5.4 until 8.2606.0, the optional mmpstrucdata plugin's parseSD_PARAM function in plugins/mmpstrucdata/mmpstrucdata.c stores RFC5424 parameter values in a fixed pVal[32 * 1024] stack buffer and calls parsePARAM_VALUE without supplying the destination size. A remote unauthenticated attacker whose crafted RFC5424 message reaches an action using mmpstrucdata can provide a structured-data parameter larger than that buffer when MaxMessageSize permits it, causing an attacker-controlled stack overwrite. Deployments that do not install and use the plugin, or whose effective message-size limit remains below the required threshold, are not affected by this issue. The demonstrated impact is a crash and interruption of log collection; code execution is not demonstrated. This issue is fixed in version 8.2606.0.

Stack Overflow

libheif 1.19.6+ Fix Op_RGB24_32_to_YCbCr Stride Overflow
CVE-2026-84449 3.7 - Low - September 18, 2026

libheif is a HEIF and AVIF file format decoder and encoder. Prior to 1.19.6, Op_RGB24_32_to_YCbCr::convert_colorspace() stores image-plane strides in an integer width that can overflow for extremely large RGB images created through heif_image_create() and heif_image_add_plane(). The resulting wrapped stride causes the conversion loop in libheif/color-conversion/rgb2yuv.cc to compute an invalid input pointer and read beyond the allocated interleaved plane while heif_context_encode_image() performs RGB-to-YCbCr conversion. This can crash the encoding process. This issue is fixed in version 1.19.6.

Integer Overflow or Wraparound

DoS via repeated decoding in libheif < 1.23.2 (grid/iovl/iden graphs)
CVE-2026-84447 7.5 - High - September 18, 2026

libheif is a HEIF and AVIF file format decoder and encoder. In 1.23.1 and earlier, crafted grid, iovl, and iden reference graphs can repeatedly decode the same base image because processed_ids is copied per branch and ImageItem::decode_image() has no shared operation budget. This vulnerability is fixed in 1.23.2.

Allocation of Resources Without Limits or Throttling

libheif 1.19.0-1.23.1 Unbounded Memory Decompressor (fixed in 1.23.2)
CVE-2026-84384 7.5 - High - September 18, 2026

libheif is a HEIF and AVIF file format decoder and encoder. From 1.19.0 until 1.23.2, crafted HEIF or AVIF mime metadata and unci image data can cause decompress_brotli() and do_inflate() to grow accumulated output without an effective size limit or MemoryHandle accounting. The brotli path has no output bound, while the zlib path checks only a small temporary buffer in a branch that valid streams do not reach, and overlapping icef units can decompress the same payload repeatedly. HeifContext::interpret_heif_file_images() processes multiple compressed metadata items during file opening, allowing a small file to consume unbounded memory and terminate the process. This issue is fixed in version 1.23.2.

Data Amplification

libheif <1.23.2: Heif Timing DoS via Track::init_sample_timing_table
CVE-2026-84446 7.5 - High - September 18, 2026

libheif is a HEIF and AVIF file format decoder and encoder. Prior to 1.23.2, crafted HEIF sequence timing and edit-list data can make Track::init_sample_timing_table() compute a logical m_num_output_samples value that exceeds the uint32_t counters used by Track_Visual::decode_next_image_sample() and Track::get_next_sample_raw_data(). The resulting comparison can never reach the oversized output count, causing non-terminating decode or raw-sample loops and bypassing max_sequence_frames. The same sequence path repeatedly calls Box_stts::get_sample_duration() and allocates Chunk::m_sample_ranges and Track::m_presentation_timeline outside MemoryHandle accounting, allowing severe CPU and memory exhaustion from a small file. This issue is fixed in version 1.23.2.

Infinite Loop

Heap Overflow in libheif<1.23.2 via heif_region_item_add_region_inline_mask_data
CVE-2026-84448 4 - Medium - September 18, 2026

libheif is a HEIF and AVIF file format decoder and encoder. Prior to 1.23.2, the public heif_region_item_add_region_inline_mask_data() function in libheif/api/libheif/heif_regions.cc accepts mask_data_len without verifying that it equals the byte count required by width and height. A later heif_region_get_mask_image() call derives the read length from the region geometry, so an undersized stored buffer causes heif_region_get_inline_mask_image() to read beyond the heap allocation and copy adjacent bytes into the returned monochrome mask image. This can disclose heap data or crash an application that constructs region metadata through the writer API, while the file-parsing path is not affected because it validates the canonical mask size. This issue is fixed in version 1.23.2.

Out-of-bounds Read

ImageMagick 7.1.2-31 UHDR Encoder Policy Bypass Causing DoS
CVE-2026-93590 6.3 - Medium - September 18, 2026

ImageMagick before 7.1.2-31 contains a policy bypass vulnerability in the UHDR encoder that fails to perform policy checks during buffer allocation for image pixels. Attackers can bypass resource policies by processing specially crafted UHDR images, potentially causing denial of service through excessive memory allocation.

Resource Exhaustion

ImageMagick <=7.1.2-31 / 6.9.13-56 FLIF Encoder Div/0 DoS
CVE-2026-93589 6.3 - Medium - September 18, 2026

ImageMagick before 7.1.2-31 and 6.9.13-56 contains a division-by-zero flaw in the FLIF encoder. An incorrect value for ticks per second in the image being encoded causes a divide-by-zero and crashes the encoder, resulting in a denial of service. The issue is fixed in 7.1.2-31 and 6.9.13-56.

Divide By Zero

ImageMagick <7.1.2-31 or <6.9.13-56 NULL Deref DoS in PNM Coder
CVE-2026-93588 2.3 - Low - September 18, 2026

ImageMagick before 7.1.2-31 and before 6.9.13-56 contains a NULL pointer dereference in the PNM coder. When the coder reaches a memory (resource) limit at a specific point during processing, the failed allocation is not handled and a NULL pointer is dereferenced, which can lead to a denial of service (application crash) when processing a specially crafted or sufficiently large PNM image.

NULL Pointer Dereference

ImageMagick 7.1.2-31/6.9.13-56 policy bypass in PCD/CUBE/HALD coders
CVE-2026-93587 4.8 - Medium - September 18, 2026

ImageMagick before 7.1.2-31 and before 6.9.13-56 contains a policy bypass in the PCD (and, per the upstream advisory, CUBE and HALD) coder: when a specific command line option is supplied, the decoder does not check a configured resource limit, which can result in extra memory allocation. A local user able to pass command line options to ImageMagick can therefore exceed the intended memory policy limit, causing a limited availability impact. The issue is fixed in 7.1.2-31 and 6.9.13-56.

Resource Exhaustion

ImageMagick 7.1.2-31 UAF in ImagesToBlob
CVE-2026-93586 2.1 - Low - September 18, 2026

ImageMagick before 7.1.2-31 and before 6.9.13-56 contains a use-after-free vulnerability in the ImagesToBlob method, caused by a pointer that is not updated correctly. Exploitation may result in a limited availability impact (e.g., a crash of the affected process). The issue is fixed in versions 7.1.2-31 and 6.9.13-56.

Dangling pointer

RabbitMQc <0.16.0: FrameUnderflowCVE202644235 in amqp_connection
CVE-2026-44235 6.5 - Medium - September 17, 2026

rabbitmq-c is a C-language AMQP client library for RabbitMQ. Prior to 0.16.0, a malicious AMQP server can send an undersized HEADER or METHOD frame during client login and cause unsigned size_t underflow in amqp_handle_input() in librabbitmq/amqp_connection.c. The parser subtracts HEADER_SIZE, fixed per-frame fields, and FOOTER_SIZE from state->target_size without first checking the minimum frame length. The wrapped encoded.len value is passed through amqp_decode_properties() to amqp_decode_table_internal(), where it defeats bounds checks and causes an out-of-bounds read and process crash. An on-path attacker can also trigger the issue when AMQP traffic is not protected by TLS with certificate validation. The demonstrated impact is denial of service, with no reliable memory disclosure or code execution shown. This issue is fixed in version 0.16.0.

Out-of-bounds Read

RabbitMQ-C <0.16.0: AMQP frame_max buffer overflow in amqp_frame_to_bytes()
CVE-2026-44236 7.1 - High - September 17, 2026

rabbitmq-c is a C-language AMQP client library for RabbitMQ. Prior to 0.16.0, a malicious AMQP server can send an undersized connection.tune.frame_max value during amqp_login(), and rabbitmq-c accepts the value in amqp_login_inner() in librabbitmq/amqp_socket.c. amqp_tune_connection() in librabbitmq/amqp_connection.c uses frame_max to reallocate the outbound buffer without enforcing AMQP_FRAME_MIN_SIZE. Immediate serialization of connection.tune-ok through amqp_frame_to_bytes() writes beyond the undersized heap allocation, causing memory corruption and likely denial of service. An on-path attacker can also trigger the flaw against plaintext AMQP traffic. Code execution is theoretically possible but was not demonstrated. This issue is fixed in version 0.16.0.

Heap-based Buffer Overflow

Linux Kernel ext4: Stale Xarray Tag Writeback Bug
CVE-2026-92502 - September 17, 2026

In the Linux kernel, the following vulnerability has been resolved: ext4: clear stale xarray tags on folios skipped during writeback In data=journal mode, the writeback thread can hit the WARN_ON_ONCE(sb_rdonly(sb)) in ext4_journal_check_start() while the superblock is being remounted read-only during reboot: Workqueue: writeback wb_workfn (flush-253:0) RIP: 0010:ext4_journal_check_start+0x8b/0xd0 Call Trace: __ext4_journal_start_sb+0x3c/0x1e0 mpage_prepare_extent_to_map+0x4af/0x580 ext4_do_writepages+0x3c0/0x1080 ext4_writepages+0xc8/0x1a0 do_writepages+0xc4/0x180 __writeback_single_inode+0x45/0x2f0 writeback_sb_inodes+0x26b/0x5d0 __writeback_inodes_wb+0x54/0x100 wb_writeback+0x1ac/0x320 wb_workfn+0x394/0x470 And followed by the warning: EXT4-fs warning (device vda1): ext4_evict_inode:195: inode #6263: comm (sd-umount): data will be lost This issue is not reproduced every time, but frequently. The reproduction step is to create a VM with 8 CPUs, 16G memory and setup data=journal: sudo tune2fs -o journal_data /dev/vda1 Run fio: rm -f fiotest fio --name=fiotest --rw=randwrite --bs=4k --runtime=6 --ioengine=libaio --iodepth=256 --numjobs=8 --filename=fiotest --filesize=30G --group_reporting Reboot the VM, and check the console output from: virsh console testvm But there is no dirty inode, folio_clear_dirty_for_io clears PG_dirty but leaves tags PAGECACHE_TAG_DIRTY and PAGECACHE_TAG_TOWRITE set which are only cleared by __folio_start_writeback. In data=journal mode, jbd2 checkpoints the journalled data to its final location and clears its own dirty flag without touching folio PG_dirty or xarray dirty flags. The commit f4a2b42e7891 ("ext4: fix stale xarray tags after writeback") fixes when PG_dirty is still set but there is no dirty page. Another case is PG_dirty is cleared, but PAGECACHE_TAG_DIRTY and PAGECACHE_TAG_TOWRITE is still set. In this case, writeback thread checks clean folio and skips it in mpage_prepare_extent_to_map: if (!folio_test_dirty(folio) || ... folio_unlcok(folio); continue And never reaches ext4_bio_write_folio where the commit f4a2b42e7891 clears the stale xarray tags. Print debug logs after the filesystem is remounted read-only: writepages RDONLY nrpages=2048 dirtytag=1 wbtag=0 towrite=1 sync=0 And all folios are actually clean: folio idx=3 dirty=0 wb=0 checked=0 dirtybuf=0 jbddirty=0 mapped=1 ... We need to clear the xarray stale tags for such clean folios by cycling them through writeback in the skip path, the same way f4a2b42e7891 does in ext4_bio_write_folio.

libxml2 NULL Pointer Deref in XML Catalog Parsing (DoS)
CVE-2026-76781 5.5 - Medium - September 17, 2026

A flaw was found in libxml2. A local user or an attacker providing a specially crafted XML catalog can trigger a NULL pointer dereference during XML catalog parsing. This occurs when a `nextCatalog` element lacks its mandatory `catalog` attribute, leading to the application crashing and causing a Denial of Service (DoS).

NULL Pointer Dereference

Unbound 1.26.0 Heap Overflow -> RCE via CNAME TTL Rewrite
CVE-2026-82717 8.4 - High - September 16, 2026

In NLnet Labs Unbound up to and including 1.26.0, a vulnerability was found in that can progressively corrupt heap memory and under certain systems and compilation options could lead to remote code execution. The vulnerability starts when CNAME synthesis during an upstream response needs to enforce(rewrite) a max TTL value in the packet buffer. Coupled with a compression pointer that points to the overwritten value and invalidates the domain name, it leads to an error path that does not properly move the buffer position and allows for the heap buffer overflow. Since this is heavily reliant on heap memory layout, results are memory corruption that eventually leads to a crash and under specific systems and compilation options remote code execution.

Heap-based Buffer Overflow

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