Canonical Ubuntu Linux Linux Operating System

libcurl SSH Key Type Mismatch Allows Silent MITM via CURLOPT_SSH_KEYFUNCTION
CVE-2026-9547 - July 03, 2026

When a libcurl-based application performs transfers via `SCP://` or `SFTP://` and utilizes the `CURLOPT_SSH_KEYFUNCTION` callback, it may silently accept an untrusted server. This vulnerability occurs when a server presents a host key type that does not match the specific key type already recorded for that host in the `known_hosts` file. Instead of rejecting the mismatch, the callback mechanism fails to properly enforce the restriction, allowing the connection to succeed without warning and risking a potential man-in-the-middle attack.

libcurl HTTP/3 session resumption EarlyData info leak
CVE-2026-9545 - July 03, 2026

In this scenario, libcurl first uses a proper HTTP/3 server for the initial transfers, and when it makes a second transfer to the same site it has been replaced by the attacker's impostor machine - without a valid certificate. When libcurl returns to the hostname the second time with a cached SSL session (`CURLOPT_SSL_SESSIONID_CACHE` is not disabled) and early data enabled (the `CURLSSLOPT_EARLYDATA` bit is set in `CURLOPT_SSL_OPTIONS`), libcurl might send off the second request's bytes on that new connection *before* enforcing the certificate verification failure. Potentially leaking sensitive information.

libcurl UAF via curl_easy_pause() in SOCKETFUNCTION
CVE-2026-9080 - July 03, 2026

Calling `curl_easy_pause()` within the event-based `CURLMOPT_SOCKETFUNCTION` callback triggers a use-after-free vulnerability, where libcurl attempts to store a flag using a dangling struct pointer immediately after that pointer's memory has been freed.

Privilege Esc Escalation: libcurl Fails to Clear Proxy Auth Credentials
CVE-2026-9079 - July 03, 2026

libcurl had a flaw that when instructed to clear proxy authentication credentials which made it not do so, leaving the old credentials around to get used for subsequent transfers that should not know nor use them.

libcurl: Proxy Auth Leakage on Reused Handles
CVE-2026-8927 - July 03, 2026

When reusing a libcurl handle for sequential transfers driven by environment-variable proxy configuration, libcurl fails to clear the proxy authentication state between requests. Specifically, if the initial transfer authenticates against `proxyA` using Digest auth, a subsequent transfer routed through `proxyB` erroneously leaks the `Proxy-Authorization:` header intended solely for `proxyA`.

curl Credential Inference via .netrc/Username Mismatch
CVE-2026-8926 - July 03, 2026

When asking curl to use a `.netrc` file to find credentials and at the same time specifying a URL with a username(without a password), like `https://user@example.com/`, curl could wrongly get and use the password for *another* user set in the `.netrc` file for that host if such a one exists and there is no match for the specified user.

cURL doublefree via GSASL context cleanup bug
CVE-2026-8925 - July 03, 2026

The curl logic that works with SASL authentication could end up cleaning up the GSASL context *twice* without clearing the pointer in between, making it `free()` the same pointer twice.

Curl Cookie Parsing Vulnerability: Super Cookies Bypass PSL
CVE-2026-8924 - July 03, 2026

A flaw in curls cookie parsing logic allows a malicious HTTP server to set 'super cookies' that bypass the Public Suffix List check. This enables an attacker-controlled origin to inject cookies that curl subsequently scopes and transmits to unrelated third-party domains.

libcurl Negotiate Authentication Connection Reuse Flaw
CVE-2026-8458 - July 03, 2026

libcurl might in some circumstances reuse the wrong connection when asked to do Negotiate-authenticated ones, even when they are set to use different 'services'. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of criteria must be met. Due to a logical error in the code, a request that was issued by an application could wrongfully reuse an existing connection to the same server that was authenticated using different services.

CURL STARTTLS Connection Reuse with TLS Mismatch
CVE-2026-8286 - July 03, 2026

A vulnerability exists where a new transfer that uses STARTTLS to upgrade the connection might reuse an existing live connection even though the TLS configuration mismatches so it should not.

containerd CRI pathtraversal bug pre2.3.2/2.2.5/2.1.9
CVE-2026-53489 - July 01, 2026

containerd is an open-source container runtime. Versions prior to 2.3.2, 2.2.5 and 2.1.9 contain a bug where the CRI plugin restores container.log from a checkpoint image without validating a symlinked path. This could result in reading an arbitrary file on the host via kubectl logs. This issue has been fixed in versions 2.3.2, 2.2.5 and 2.1.9.

Symlink following

containerd CDI Annotation Injection via Untrusted Checkpoints (pre-2.3.2)
CVE-2026-53492 - July 01, 2026

containerd is an open-source container runtime. In Versions prior to 2.3.2, 2.2.5 and 2.1.9, the CRI implementation improperly trusts Container Device Interface (CDI) annotations found within untrusted checkpoint image metadata during container restoration. When restoring a container from a checkpoint, containerd preserves CDI-related annotations from the checkpoint archive rather than relying solely on the pod's create-time specification. This allows a user with pod creation permissions to bypass standard Kubernetes resource allocation and device plugin enforcement, injecting arbitrary CDI edits (such as device nodes and host mounts) into the restored container. Successful exploitation requires that the node has CDI enabled and contains a matching host CDI specification for the requested device; environments where CDI is disabled or lacking sensitive device specifications are not affected. This issue has been fixed in versions 2.3.2, 2.2.5 and 2.1.9.

Improper Input Validation

containerd CRI Checkpoint Image Cache Poisoning (v<2.3.2,2.2.5,2.1.9)
CVE-2026-50195 - July 01, 2026

containerd is an open-source container runtime. Versions prior to 2.3.2, 2.2.5 and 2.1.9 contain a vulnerability in the CRI checkpoint import process where it fails to validate the image references specified within a checkpoint image's configuration. An attacker with permissions to create pods can use a crafted checkpoint image to force containerd to pull a malicious image and assign it an arbitrary local tag, thereby poisoning the node's local image cache. Subsequently, if other pods on the same node attempt to use the poisoned tag with an IfNotPresent (or Never) pull policy, they will unknowingly execute the attacker's malicious image instead of the legitimate one. This can lead to a compromise of the affected pods, allowing the attacker to execute arbitrary code under the victim pod's identity. This issue has been fixed in versions 2.3.2, 2.2.5 and 2.1.9.

Insufficient Verification of Data Authenticity

containerd DoS via faulty image load causing OOM kill (v<1.7.33,2.0.10,2.1.9)
CVE-2026-47262 - July 01, 2026

containerd is an open-source container runtime. Versions prior to 1.7.33, 2.0.10, 2.1.9, 2.2.5 and 2.3.2, contain a vulnerability that allows a maliciously crafted image to cause a Denial of Service (DoS) condition. When creating a container from this image, memory exhaustion occurs, leading to an Out Of Memory (OOM) kill of the containerd process. This renders the container runtime API unavailable and can disrupt clients such as the Docker Engine or Kubernetes control-plane components. This issue has been fixed in versions 1.7.33, 2.0.10, 2.1.9, 2.2.5 and 2.3.2.

Resource Exhaustion

CRI Label Injection in containerd 1.7.x/2.0-2.3 (1.7.33/2.3.2)
CVE-2026-53488 - July 01, 2026

containerd is an open-source container runtime. In versions prior to 1.7.33, 2.3.2, 2.2.5, 2.1.9, and 2.0.10 the CRI plugin propagates labels from an image config (LABEL instruction in Dockerfile) to a container without validation. This may result in executing an arbitrary command on the host, via a plugin that consumes container labels for some operations. This issue has been fixed in versions 1.7.33, 2.3.2, 2.2.5, 2.1.9, and 2.0.10.

Improper Input Validation

Vim Stack OOB Write CVE-2026-55693 (before 9.2.0653) in spellfile.c
CVE-2026-55693 - June 25, 2026

Vim is an open source, command line text editor. Prior to 9.2.0653, the tree_count_words() function in src/spellfile.c fills in the word-count fields of a spell-file word trie by walking it iteratively with a depth counter. The counter is bounded only by the trie structure itself; it is never checked against the size of the fixed MAXWLEN-element stack arrays it indexes (arridx[], curi[], wordcount[]). A crafted .spl/.sug file pair, loaded when the user invokes spell suggestion, can drive the descent arbitrarily deep, so the function writes past the end of those arrays. This is a stack out-of-bounds write that corrupts the call frame and crashes the editor. This vulnerability is fixed in 9.2.0653.

Memory Corruption

Vim <=9.2.0661 Stack OOB Write in dump_prefixes() (spell.c)
CVE-2026-55892 5.5 - Medium - June 25, 2026

Vim is an open source, command line text editor. Prior to 9.2.0662, the dump_prefixes() function in src/spell.c walks a spell-file prefix trie iteratively with a depth counter while dumping the prefixes that apply to a word. The counter is bounded only by the trie structure itself; it is never checked against the size of the fixed MAXWLEN-element stack arrays it indexes (prefix[], arridx[], curi[]). A crafted .spl file, loaded when the user dumps the word list, can drive the descent arbitrarily deep, so the function writes past the end of those arrays. This is a stack out-of-bounds write that corrupts the call frame and crashes the editor. This vulnerability is fixed in 9.2.0662.

Memory Corruption

Vim <=9.2.0662 Netrw LocalRmFile Vimscript Injection
CVE-2026-55895 - June 25, 2026

Vim is an open source, command line text editor. Prior to 9.2.0663, a Vimscript code injection vulnerability exists in s:NetrwLocalRmFile() in the netrw plugin (runtime/pack/dist/opt/netrw/autoload/netrw.vim) when deleting a local file from the browser. A filename derived from the buffer's directory listing is interpolated into an Ex command line passed to :execute with only the backslash character escaped, allowing a crafted filename containing a bar (|) to terminate the intended command and execute arbitrary Vimscript, including shell commands via :call system() and :!. This vulnerability is fixed in 9.2.0663.

Shell injection

Vim 9.2.0671: Decryption Underflow Crash (VimCrypt~04/05)
CVE-2026-57452 5.5 - Medium - June 25, 2026

Vim is an open source, command line text editor. Prior to 9.2.0671, when Vim opens a file encrypted with the VimCrypt~04! or VimCrypt~05! method (xchacha20poly1305, requires the +sodium feature) whose body is shorter than a single libsodium secretstream header, an unsigned length calculation underflows and a subsequent decryption call reads far past the end of the input buffer, crashing Vim. This vulnerability is fixed in 9.2.0671.

Out-of-bounds Read

Vim 9.1.1784-9.2.0678 PowerShell command injection via zip plugin
CVE-2026-57453 6.5 - Medium - June 25, 2026

Vim is an open source, command line text editor. From 9.1.1784 until 9.2.0678, when the bundled zip plugin autoload/zip.vim falls back to PowerShell to browse, read, extract, update or delete entries in a zip archive, it builds the PowerShell command by inserting archive entry names that are quoted only for the shell, not for PowerShell. A crafted entry name can break out of the intended string context and cause PowerShell to execute arbitrary commands with the privileges of the user running Vim, triggered by opening, viewing or extracting the archive. This vulnerability is fixed in 9.2.0678.

Command Injection

Stack OOB Write in Vim <9.2.0698, spell.c SOFO Handling
CVE-2026-57455 - June 25, 2026

Vim is an open source, command line text editor. Prior to 9.2.0698, the single-byte branch of spell_soundfold_sofo() in src/spell.c translates a word through a spell file's SOFO (sound-folding) byte map into a caller-owned result buffer. Its copy loop advances the output index ri with no upper bound and terminates only on the input NUL, writing one byte per input byte into the MAXWLEN-element stack buffer the caller provides. A word longer than MAXWLEN, passed to soundfold() (or reached via sound-based spell suggestion) while a SOFO-based spell language is active, therefore writes past the end of that buffer. This is a stack out-of-bounds write that corrupts the call frame and crashes the editor. This vulnerability is fixed in 9.2.0698.

Memory Corruption

Vim<9.2.0699 : Python omnicompletion exec() injection
CVE-2026-57456 - June 25, 2026

Vim is an open source, command line text editor. Prior to 9.2.0699, Vim's Python omni-completion (runtime/autoload/python3complete.vim and the legacy pythoncomplete.vim) executes reconstructed function and class definitions from the current buffer with exec() as part of populating the completion dictionary. When reconstructing that source, each scope's docstring is inserted verbatim between triple quotes with no escaping, so a hostile buffer can break out of the triple-quoted literal and execute attacker-controlled Python during omni-completion. This vulnerability is fixed in 9.2.0699.

Code Injection

Linux kernel overlay readdir bug: bogus non-zero error from PTR_ERR
CVE-2026-53174 7.8 - High - June 25, 2026

In the Linux kernel, the following vulnerability has been resolved: ovl: keep err zero after successful ovl_cache_get() ovl_iterate_merged() stores PTR_ERR(cache) in err before checking IS_ERR(cache). On success err holds the truncated cache pointer and can be returned as a bogus non-zero error. The syzbot reproducer reaches this through overlay-on-overlay readdir: getdents64 iterate_dir(outer overlay file) ovl_iterate_merged() ovl_cache_get() ovl_dir_read_merged() ovl_dir_read() iterate_dir(inner overlay file) ovl_iterate_merged() Only compute PTR_ERR(cache) on the error path.

NSD 4.10.1-4.14.3 TLS Auth Name Bypass on Secondary XFR
CVE-2026-12490 - June 25, 2026

When a provide-xfr is given with a tls-auth-name, a secondary requesting a transfer should provide a client certificate with that name. However, no client certificate is needed when the request comes in over TLS over the regular tls-port (and not the tls-auth-port) or over over TCP over the regular port, when the other conditions of the provide-xfr rule match.

Missing Authentication for Critical Function

NSD 4.14.0-4.14.2 Stack Overwrite via APL RR (adflength)
CVE-2026-12246 - June 25, 2026

NSD version 4.14.0 introduced a bug where a specially crafted APL RR, with an adflength larger than permitted for the address family will overwrite the stack when the zone is written to disk, with a maximum of 111 attacker controlled bytes.

Classic Buffer Overflow

NSD 4.13.0 Heap UAF via TLS Logging on DoT
CVE-2026-12245 - June 25, 2026

NSD from version 4.13.0 has a heap use-after-free bug in logging errors on TLS connections, causing a crash of the server process, which can be triggered trivially by sending a DNS query over a DoT connection, and closing the connection without reading the response.

Dangling pointer

NSD 4.14.0-4.14.2: AXFR SVCB RR Heap Overflow RCE
CVE-2026-12244 - June 25, 2026

If NSD is configured as secondary for a zone, the primary of that zone can crash NSD with an AXFR containing a DNS message with a special crafted SVCB RR with an rdata size of 65512, that let's an (uint16_t) variable that is used to allocate space needed for the RR wrap (because total size > 65535), causing a heap overflow. The attacker can perform a controlled (RCE class) head write of up to 65509 bytes

Integer Overflow or Wraparound

Linux Kernel io_uring Poll Ref Signed Comparison Bug Fixed
CVE-2026-52933 7.8 - High - June 24, 2026

In the Linux kernel, the following vulnerability has been resolved: io_uring/poll: fix signed comparison in io_poll_get_ownership() io_poll_get_ownership() uses a signed comparison to check whether poll_refs has reached the threshold for the slowpath: if (unlikely(atomic_read(&req->poll_refs) >= IO_POLL_REF_BIAS)) atomic_read() returns int (signed). When IO_POLL_CANCEL_FLAG (BIT(31)) is set in poll_refs, the value becomes negative in signed arithmetic, so the >= 128 comparison always evaluates to false and the slowpath is never taken. Fix this by casting the atomic_read() result to unsigned int before the comparison, so that the cancel flag is treated as a large positive value and correctly triggers the slowpath.

libheif <=1.22.1 OOB Heap Read via Wrapped Offset in HEIF
CVE-2026-49271 6.5 - Medium - June 19, 2026

libheif is a HEIF and AVIF file format decoder and encoder. Prior to version 1.22.1, the uncompressed HEIF decoder validates explicit icef compressed-unit offsets using unit_offset + unit_size. Because the addition can wrap, a crafted HEIF file can pass the range check and then construct a vector from iterators outside the compressed item buffer, producing an out-of-bounds heap read and crash. Version 1.22.1 patches the issue.

Out-of-bounds Read

QEMU virtio-snd Input Callback Heap OOB Write CVE-2026-3195
CVE-2026-3195 7.4 - High - June 19, 2026

A flaw was found in QEMU. When reading input audio in the virtio-snd device input callback, the `virtio_snd_pcm_in_cb` function did not check whether the iov could fit the data buffer, potentially leading to a heap out-of-bounds write. This issue exists due to an incomplete fix for CVE-2024-7730.

Heap-based Buffer Overflow

Virtio-snd Integer Overflow Host DoS via PCM_INFO
CVE-2026-3196 5.5 - Medium - June 19, 2026

An integer overflow vulnerability was found in the virtio-snd device via PCM_INFO requests from the guest. A malicious guest can provide out-of-bounds stream counts, potentially leading to unbounded memory allocation on the host and a denial of service condition.

Integer Overflow or Wraparound

libssh2 <=1.11.1 OOB Heap Read in sftp_symlink() (SSH_FXP_NAME over-read)
CVE-2025-15661 6.5 - Medium - June 18, 2026

libssh2 through 1.11.1, fixed in commit 2dae302, contains an out-of-bounds heap read vulnerability in the sftp_symlink() function in src/sftp.c that allows a malicious SSH server or man-in-the-middle attacker to disclose heap memory contents or cause a crash by sending a crafted SSH_FXP_NAME response. Attackers can supply a link_len value larger than the actual packet data in SSH_FXP_NAME responses for SFTP READLINK and REALPATH operations, triggering a heap buffer over-read of up to target_len minus one bytes due to the missing validation of available packet buffer size before the memcpy operation.

Out-of-bounds Read

libssh2 1.11.1 OOB Write in ssh2_transport_read() via oversized packet_length
CVE-2026-55200 8.1 - High - June 17, 2026

libssh2 through 1.11.1, fixed in commit 7acf3df contains an out-of-bounds write vulnerability in ssh2_transport_read() that fails to enforce upper bounds on packet_length field. Remote attackers can send crafted SSH packets with excessively large packet_length values to corrupt heap memory and achieve remote code execution.

Integer Overflow to Buffer Overflow

libssh2 <=1.11.1 SSH_MSG_EXT_INFO Pre-auth CPU DoS
CVE-2026-55199 5.9 - Medium - June 17, 2026

libssh2 through 1.11.1, fixed in commit 1762685, contains a pre-authentication denial of service vulnerability in the SSH_MSG_EXT_INFO handler in src/packet.c that allows a malicious SSH server to cause a client CPU exhaustion loop by sending a crafted extension count value. A malicious server can set nr_extensions to 0xFFFFFFFF during key exchange, causing the client to spin in a tight CPU loop for over 60 seconds because return values from _libssh2_get_string() are unchecked and the session timeout does not apply to CPU-bound loops.

Infinite Loop

GnuTLS UAF in pkcs11_token_set_pin on NULL SO PIN
CVE-2026-42014 6.6 - Medium - June 16, 2026

A flaw was found in GnuTLS. The `gnutls_pkcs11_token_set_pin` function, used for changing the Security Officer PIN, can lead to a use-after-free vulnerability. This occurs when an attacker attempts to change the PIN with a NULL old PIN for a token that lacks a protected authentication path.

Dangling pointer

Vim <9.2.0597 Python Omni-Completion exec() Arbitrary Code Exec
CVE-2026-52860 8 - High - June 11, 2026

Vim is an open source, command line text editor. Prior to version 9.2.0597, Vim's Python omni-completion executes reconstructed function and class definitions from the current buffer with exec() as part of populating the completion dictionary. Python evaluates function default values, parameter annotations, and class base expressions at definition time, so a hostile buffer can execute attacker-controlled Python expressions during omni-completion. The existing g:pythoncomplete_allow_import mitigation (GHSA-52mc-rq6p-rc7c) does not cover this path, because the attacker-controlled code is not a harvested import/from statement. This issue has been patched in version 9.2.0597.

Code Injection

Vim 9.2 <9.2.0565 terminal snapshot buffer overflow
CVE-2026-52859 - June 11, 2026

Vim is an open source, command line text editor. Prior to version 9.2.0565, the update_snapshot() function in src/terminal.c copies the visible terminal screen into the scrollback buffer when a snapshot is taken. For each screen cell it walks the cell's chars[] array with no upper bound, stopping only when it encounters a NUL terminator. When a cell legitimately fills all VTERM_MAX_CHARS_PER_CELL (6) slots a base character plus five combining marks the bundled libvterm returns the array without a terminating NUL, so the loop reads past the fixed six-element array and appends the out-of-bounds values to a buffer reserved for only six characters. A program whose output is rendered inside a :terminal window can trigger this with a short byte sequence and no Vim scripting, leading to a crash. This issue has been patched in version 9.2.0565.

Out-of-bounds Read

Vim <9.2.0561 python3complete.vim runs local Python code (CVE-2026-52858)
CVE-2026-52858 - June 11, 2026

Vim is an open source, command line text editor. Prior to version 9.2.0561, the Python omni-completion script in python3complete.vim for Vim with the +python3 interpreter enabled (and the legacy pythoncomplete.vim for builds with the +python interpreter) executes the import and from statements found in the current buffer through Python's import machinery. Because the buffer's working directory is on sys.path, opening a hostile .py file with a sibling Python package and invoking omni-completion runs that package's top-level code as the editing user. This issue has been patched in version 9.2.0561.

Code Injection

Vim 9.2.0495 Patch: Netrw Script Injection via History File
CVE-2026-47162 7.3 - High - June 11, 2026

Vim is an open source, command line text editor. Prior to version 9.2.0495, a Vimscript code injection vulnerability exists in s:NetrwBookHistSave() in the netrw plugin (runtime/pack/dist/opt/netrw/autoload/netrw.vim) when serializing browsed directory paths to the history file ~/.vim/.netrwhist. A directory name derived from the filesystem is interpolated into a single-quoted Vimscript string literal without escaping embedded single quotes, allowing a crafted directory name to break out of the string context and execute arbitrary Vimscript, including shell commands via system() and :!, the next time the history file is sourced. This issue has been patched in version 9.2.0495.

Injection

Vim <=9.2.0495: Ruby eval injection via cucumber.vim
CVE-2026-47167 - June 11, 2026

Vim is an open source, command line text editor. Prior to version 9.2.0496, a code injection vulnerability exists in s:stepmatch() in the cucumber filetype plugin (runtime/ftplugin/cucumber.vim) on Vim builds with +ruby support. Step-definition patterns read from .rb files under the repository's features/*/ or stories/*/ directories are embedded into a Ruby Kernel.eval argument without sufficient escaping, allowing a crafted pattern in an attacker-controlled repository to execute arbitrary Ruby (and through it arbitrary shell commands) when the user invokes a step-jump mapping ([d, ]d). This issue has been patched in version 9.2.0496.

Code Injection

Jun 2026: ASP.NET Core Denial of Service Vulnerability
CVE-2026-45591 7.5 - High - June 09, 2026

Uncontrolled resource consumption in ASP.NET Core allows an unauthorized attacker to deny service over a network.

Resource Exhaustion

Jun 2026: .NET Tampering Vulnerability
CVE-2026-45491 6.2 - Medium - June 09, 2026

Improper link resolution before file access ('link following') in .NET allows an unauthorized attacker to perform tampering locally.

insecure temporary file

OpenSSL PKCS#7 UAF via PKCS7_verify(); FIPS 3.6+ safe
CVE-2026-45447 8.1 - High - June 09, 2026

Issue summary: A specially crafted PKCS#7 or S/MIME signed message could trigger a use-after-free during PKCS#7 signature verification. Impact summary: A use-after-free may result in process crashes, heap corruption, or potentially remote code execution. When processing a PKCS#7 or S/MIME signed message, if the SignedData digestAlgorithms field is present as an empty ASN.1 SET, OpenSSL may incorrectly free a caller-owned BIO during PKCS7_verify(). A subsequent use of the BIO by the calling application results in a use-after-free condition. In the common case this occurs when the application later calls BIO_free() on the BIO originally passed to PKCS7_verify(). Depending on allocator behavior and application-specific BIO usage patterns, this may result in a crash or other memory corruption. In some application contexts this may potentially be exploitable for remote code execution. Applications that process PKCS#7 or S/MIME signed messages using OpenSSL PKCS#7 APIs may be affected. Applications using the CMS APIs for this processing are not affected. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.

Dangling pointer

OpenSSL EVP Provider: AESSIV/AESGCMSIV Auth Forger via Empty AAD/Ciphertext (<3.2)
CVE-2026-45446 4.8 - Medium - June 09, 2026

Issue summary: The implementations of AES-SIV (RFC 5297) and AES-GCM-SIV (RFC 8452) mishandle the authentication of AAD (Additional Authenticated Data) with an empty ciphertext allowing a forgery of such messages. Impact summary: An attacker can forge empty messages with arbitrary AAD to the victim's application using these ciphers. AES-SIV (RFC 5297) and AES-GCM-SIV (RFC 8452) are nonce-misuse-resistant AEAD modes: they accept a key, nonce, optional AAD (bytes that are authenticated but not encrypted), and plaintext, and produces ciphertext plus a 16-byte tag. On decrypt, `EVP_DecryptFinal_ex()` is documented to return success only if the tag is verified succesfully. In OpenSSL's provider implementation of these ciphers, the expected tag is computed only when decryption function is invoked with non-empty data. If the caller supplies AAD and then calls `EVP_DecryptFinal_ex()` without invocation of the ciphertext update, which can happen when the received ciphertext length is zero, the tag is never recalculated and still holds its all-zeros value. When AES-GCM-SIV is used, an attacker who sends arbitrary AAD, empty ciphertext, and all-zeros tag passes authentication under any key they do not know, single-shot. When AES-SIV is used, for mounting the attack it's necessary for the application to reuse the decryption context without resetting the key. AES-SIV is implemented since OpenSSL 3.0. AES-GCM-SIV is implemented since OpenSSL 3.2. No protocols implemented in OpenSSL itself (TLS/CMS/PKCS7/HPKE/QUIC) support either AES-GCM-SIV or AES-SIV. To mount an attack, the applications must implement their own protocol and use the EVP interface. Also they must skip the ciphertext update when a message with an empty ciphertext arrives. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this issue, as these algorithms are not FIPS approved and the affected code is outside the OpenSSL FIPS module boundary.

Missing Cryptographic Step

OpenSSL EVP_Cipher One-Shot API Discards IV causing AES-OCB nonce reuse
CVE-2026-45445 7.5 - High - June 09, 2026

Issue summary: When an application drives an AES-OCB context through the public EVP_Cipher() one-shot interface, the application-supplied initialisation vector (IV) is silently discarded. Impact summary: Every message encrypted under the same key uses the same effective nonce regardless of the IV supplied by the caller, resulting in (key, nonce) reuse and loss of confidentiality. If the same code path is used to compute the authentication tag, the tag depends only on the (key, IV) pair and not on the plaintext or ciphertext, allowing universal forgery of arbitrary ciphertext from a single captured message. OpenSSL provides two ways to drive a cipher: the documented streaming interface (EVP_CipherUpdate / EVP_CipherFinal_ex) and a lower-level one-shot, EVP_Cipher(), whose documentation explicitly recommends against use by applications in favour of EVP_CipherUpdate() and EVP_CipherFinal_ex(). The OCB provider's streaming handler flushes the application-supplied IV into the OCB context before processing data; the one-shot handler did not. Every call to EVP_Cipher() on an AES-OCB context therefore ran with the all-zero key-derived offset state left by cipher initialisation, regardless of the caller's IV. If EVP_EncryptFinal_ex() is subsequently used to obtain the authentication tag, the deferred IV setup runs at that point and clears the running checksum that should have been accumulated over the plaintext. The resulting tag is a function of (key, IV) only and verifies against any ciphertext produced under the same (key, IV) pair. The OpenSSL SSL/TLS implementation is not affected: AES-OCB is not a TLS cipher suite, and libssl does not call EVP_Cipher() in any case. Applications that drive AES-OCB through the documented streaming AEAD API (EVP_CipherUpdate / EVP_CipherFinal_ex) are not affected. Only applications that combine the AES-OCB cipher with the EVP_Cipher() one-shot API are vulnerable. The FIPS modules in 4.0, 3.6, 3.5, 3.4 and 3.0 are not affected by this issue, as AES-OCB is outside the OpenSSL FIPS module boundary.

Missing Cryptographic Step

OpenSSL FIPS 3.0-4.0 DHX X9.42 subgroup check flaw
CVE-2026-42770 3.7 - Low - June 09, 2026

Issue summary: When EVP_PKEY_derive_set_peer() is called with a DHX (X9.42) peer key, the peer key is not properly checked for the subgroup membership. Impact summary: A malicious peer which presents an X9.42 key carrying the victim's p and g parameters, a forged q = r (a small prime factor of the cofactor (p1)/q_local), and a public value Y of order r can recover the victim's private key after a small number of key exchange attempts. When EVP_PKEY_derive_set_peer() is called with a DHX (X9.42) peer key, the subgroup membership check Y^q 1 (mod p) is performed using the peer's own q parameter, not the local key's q. The peer's domain parameters are then matched against the domain parameters of the private key, but the value of q is not compared. A malicious peer who presents an X9.42 key carrying the victim's p, g, a forged q = r (a small prime factor of the cofactor), and a public value Y of order r passes all checks. The shared secret then takes only r distinct values, leaking priv mod r. Repeating for each small-prime factor of the cofactor and combining via CRT recovers the full private key (LimLee / small-subgroup-confinement attack). The realistic attack surface is narrow: principally CMP deployments with long-lived RA/CA DHX keys and bespoke enterprise or government applications using X9.42 DHX static keys with interactive protocols and therefore this issue was assigned Low severity. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are affected by this issue.

Missing Cryptographic Step

OpenSSL CMP Root CA Key Update Validation Bypass RA Cred Escalation
CVE-2026-42769 5.3 - Medium - June 09, 2026

Issue Summary: An error in the callback used to verify the certificate provided in a Root CA key update Certificate Management Protocol (CMP) message response rendered the certificate validation ineffectual, which could lead to escalation of credentials from the Registration Authority (RA) level to the root Certification Authority (root CA) level. Impact Summary: The Registration Autority could replace the root CA certificate for the CMP clients with an arbitrary root CA certificate. One of the parts of the Certificate Management Protocol (CMP), specified in RFC 9810, is Root Certification Authority (root CA) key Rollover, which is sent by the server in a message with type 'id-it-rootCaKeyUpdate'. As part of these messages, 'newWithOld' certificate, the new root CA certificate signed with the old root CA key, is provided, and verifying its signature is crucial for transferring the trust from the old CA key to the new one. The 'id-it-rootCaKeyUpdate' messages are expected to be processed with OSSL_CMP_get1_rootCaKeyUpdate(), that is expected to verify the 'newWithOld' certificate. A typo in the certificate chain building code led to adding an incorrect certificate ('newWithOld' instead of 'oldRoot') to the certificate chain, rendering the certificate verification process ineffectual (only the issuer name and the algorithm OIDs were verified by other parts of the verification code). An attacker who already has credentials that satisfy the CMP message protection checks can generate a new key pair and use a crafted self-signed certificate in its 'id-it-rootCaKeyUpdate' CMP messages which affected CMP clients would accept as a new trust anchor. Significant preconditions for the attack (having valid RA-level credentials) are the reason the issue was assigned Low severity. The FIPS modules are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.

Improper Certificate Validation

OpenSSL <3.2 CMS PKCS7 Bleichenbacher Oracle
CVE-2026-42768 3.7 - Low - June 09, 2026

Issue summary: The CMS_decrypt and PKCS7_decrypt functions are vulnerable to Bleichenbacher-style attack when an attacker is able to provide the CMS or S/MIME messages and observe the error code and/or decryption output. Impact summary: The Bleichenbacher-style attack allows an attacker to use the victim's vulnerable application as a way to decrypt or sign messages with the victim's private RSA key. The attack is possible in 2 variants. 1. The decryption API (CMS_decrypt(), PKCS7_decrypt()) is used without providing the recipient certificate. In this case OpenSSL iterates over every KeyTransRecipientInfo (KTRI) without stopping at the first success. An attacker who authors a message with two KTRI entries the first one wrapping a real CEK under the victim's public key, the second with an arbitrary probe ciphertext obtains opportunity to iterate the 2nd KTRI to get a valid PKCS#1 v1.5 padding if the error code of the application is available. That is a Bleichenbacher oracle (Bleichenbacher, CRYPTO '98): an adaptive-chosen-ciphertext side channel from which the attacker decrypts any RSA ciphertext to the victim's key or forges any PKCS#1 v1.5 signature under it. 2. When the decryption API (CMS_decrypt(), PKCS7_decrypt()) is provided with the recipient certificate, and the recipient is not found, a random key is substituted. An attacker who authors a message and is able to compare both error code and the result of the decryption, can mount a Bleichenbacher oracle. We are not aware of any applications that provide a remote attacker an opportunity to mount an attack described in these scenarios. We consider the existence of such application very unlikely, and for this reason this CVE has been evaluated as Low severity. To avoid these attacks, when RSA PKCS#1 v1.5 Key Transport is in use, the invoked EVP_PKEY_decrypt() will use the implicit rejection mechanism described in draft-irtf-cfrg-rsa-guidance. In previous OpenSSL releases the implicit rejection was explicitly disabled. The implicit rejection mechanism always returns a plaintext value, the symmetric key. This result is deterministic for the ciphertext and the private key. The length of the decryption result can happen to match the length of the key of the symmetric cipher that was used for the content encryption. When a certificate is not provided, the last RecipientInfo producing a key that looks valid will be used. It may cause getting garbage content on decryption. As a proper way to deal with this a recipient certificate has to be provided to identify the particular RecipientInfo for decryption. The FIPS modules in 4.0, 3.6, 3.5, and 3.4 are not affected by this issue, as CMS and S/MIME processing happens outside the OpenSSL FIPS module boundary.

Covert Channel

OpenSSL CMP Client Null Deref DoS (pre-3.5) via crafted EncryptedValue OID
CVE-2026-42767 5.9 - Medium - June 09, 2026

Issue summary: An attacker-controlled CMP (Certificate Management Protocol) server could trigger a NULL pointer dereference in a CMP client application. Impact summary: A NULL pointer dereference causes a crash of the application and a Denial of Service. An attacker controlling a CMP server (or acting as a man-in-the-middle) could craft a CMP response containing a CRMF (Certificate Request Message Format) CertRepMessage with an EncryptedValue structure where the symmAlg field has an algorithm OID but no parameters field. When the OpenSSL CMP client processes this response, the NULL dereference occurs, causing a crash of the CMP client. Applications that process untrusted CMP/CRMF messages may be affected. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.

NULL Pointer Dereference

OpenSSL CMS NULL Deref (before 4.0) - DoS
CVE-2026-42766 5.9 - Medium - June 09, 2026

Issue summary: A specially crafted password-encrypted CMS message can trigger a NULL pointer dereference during CMS decryption. Impact summary: This NULL pointer dereference leads to an application crash and a Denial of Service. The CMS PasswordRecipientInfo.keyDerivationAlgorithm field is defined as OPTIONAL in the ASN.1 specification and may therefore be absent in specially crafted inputs. During the password-based CMS decryption the OpenSSL CMS implementation dereferences this field without first checking whether it was present. An attacker who supplies such a CMS message to an application performing password-based CMS decryption can trigger an application crash, leading to a Denial of Service. Applications that process password-encrypted CMS messages may be affected. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.

NULL Pointer Dereference