Canonical Ubuntu Linux Linux Operating System

A flaw was found in Samba
CVE-2026-4408 9 - Critical - May 28, 2026

A flaw was found in Samba. A remote attacker can exploit a misconfiguration in Samba file servers and classic domain controllers that use the "check password script" feature. If this script is configured with the %u substitution character, the client-controlled username is passed without proper escaping of shell meta-characters. This vulnerability allows an attacker to achieve remote command execution on the affected system. This issue primarily affects non-standard configurations where the "check password script" is used with %u and the samba-dcerpcd service is started as a system service.

Shell injection

Samba NTFS Reparse Points Access Control Bypass via SMB
CVE-2026-1933 7.1 - High - May 27, 2026

A flaw was found in Sambas handling of NTFS-style reparse points on shares configured with read only = yes. Due to missing SMB-layer access checks, authenticated users with underlying filesystem write permissions may create or delete reparse point metadata through SMB operations even on read-only exports. This could allow modification of SMB-visible file behavior, including converting files into symbolic links or other reparse point types.

Authorization

Sambas vfs_worm Rename Bypass Enables Overwrite of WORM Files
CVE-2026-2340 6.5 - Medium - May 27, 2026

A flaw was found in Sambas vfs_worm module. The module is intended to provide write-once, read-many (WORM) protections by preventing modification of files after a configurable grace period. Due to insufficient validation during rename operations, an authenticated user with write access to a share could overwrite a protected file by renaming a newly created file over the existing WORM-protected file.

Improper Handling of Insufficient Permissions or Privileges

Samba CA AutoEnroll HTTP Trust Misinstall (CVE-2026-3012)
CVE-2026-3012 8 - High - May 27, 2026

A flaw was found in Sambas certificate auto-enrollment Group Policy handling. When certificate auto-enrollment is enabled, Samba may retrieve a CA certificate over an unencrypted HTTP connection and install it into the local trust store without proper verification. An attacker with the ability to intercept or redirect network traffic could exploit this behavior to supply a malicious certificate authority certificate, potentially allowing interception or spoofing of trusted communications.

Insufficient Verification of Data Authenticity

GnuTLS PKCS#12 Bag Off-by-One Buffer Overwrite
CVE-2026-42015 5.3 - Medium - May 26, 2026

A flaw was found in gnutls. An off-by-one error exists in the PKCS#12 bag element bounds check. This vulnerability allows an remote attacker to write past the internal array of a PKCS#12 bag when appending to a bag that already contains 32 elements. This memory corruption could lead to a denial of service (DoS) or potentially other unspecified impacts.

off-by-five

GnuTLS SAN Size ForkCheck Bypass
CVE-2026-42013 8.2 - High - May 26, 2026

A flaw was found in gnutls. When validating certificates, an oversized Subject Alternative Name (SAN) could cause the validation process to incorrectly fall back to checking the Common Name (CN) field. This could allow a remote attacker to bypass proper certificate validation, potentially leading to spoofing or man-in-the-middle attacks.

Improper Validation of Specified Quantity in Input

GNUTLS Certificate Validation Bypass via URI/SRV SAN Fallback
CVE-2026-42012 7.1 - High - May 26, 2026

A flaw was found in gnutls. A remote attacker could exploit this vulnerability by presenting a specially crafted certificate that contains Uniform Resource Identifier (URI) or Service (SRV) Subject Alternative Names (SANs). This could cause the certificate validation process to incorrectly fall back to checking DNS hostnames against the Common Name (CN), potentially allowing the attacker to spoof legitimate services or intercept sensitive information.

Improper Certificate Validation

Libgnutls RSA PKCS#11 Key Exchange Overread Info Disclosure
CVE-2026-5260 8.2 - High - May 26, 2026

A flaw was found in libgnutls. A remote attacker, by sending an extremely short premaster secret during an RSA key exchange to a server using an RSA key backed by a PKCS#11 token, could trigger a short heap overread. This memory corruption vulnerability could lead to information disclosure.

Improper Validation of Specified Quantity in Input

Shell Injection in Samba Print Service via Unescaped %J
CVE-2026-4480 8.5 - High - May 26, 2026

A flaw was found in the Samba printing subsystem. Samba passes the client-controlled job description string to the command configured with the "print command" setting via the "%J" substitution character without escaping shell meta characters. A remote attacker could exploit this vulnerability by sending a specially crafted print job description that contains unescaped shell characters. This could lead to remote code execution on the affected system.

Shell injection

BIND 9 Unbounded Resend Loop Causing Resource Exhaustion (9.18.369.18.48)
CVE-2026-5950 5.3 - Medium - May 20, 2026

An unbounded resend loop vulnerability exists in the BIND 9 resolver state machine during bad-server handling, enabling a remote unauthenticated attacker to cause severe resource exhaustion by sending queries that trigger specific retry conditions. This issue affects BIND 9 versions 9.18.36 through 9.18.48, 9.20.8 through 9.20.22, 9.21.7 through 9.21.21, 9.18.36-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1.

Unchecked Input for Loop Condition

BIND9 9.20.0-9.21.21/use-after-free via SIG(0) race during recursiveclient limit
CVE-2026-5947 7.5 - High - May 20, 2026

Undefined behavior may result due to a race condition leading to a use-after-free violation. If BIND receives an incoming DNS message signed with SIG(0), it begins work to validate that signature. If, during that validation, the "recursive-clients" limit is reached (as would occur during a query flood), and that same DNS message is discarded per the limit, there is a brief window of time while the SIG(0) validation may attempt to read the now-discarded DNS message. This issue affects BIND 9 versions 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, and 9.20.9-S1 through 9.20.22-S1. BIND 9 versions 9.18.28 through 9.18.49 and 9.18.28-S1 through 9.18.49-S1 are NOT affected.

Race Condition

BIND 9 named Assertion Failure on Non-IN DNS Messages 9.119.21 CVE-2026-5946
CVE-2026-5946 7.5 - High - May 20, 2026

Multiple flaws have been identified in `named` related to the handling of DNS messages whose CLASS is not Internet (`IN`) for example, `CHAOS` or `HESIOD`, or DNS messages that specify meta-classes (`ANY` or `NONE`) in the question section. Specially crafted requests reaching the affected code paths recursion, dynamic updates (`UPDATE`), zone change notifications (`NOTIFY`), or processing of `IN`-specific record types in non-`IN` data can cause assertion failures in `named`. This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.48, 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1.

Improper Input Validation

Use-After-Free in BIND 9 DoH (9.20.09.20.22 / 9.21.09.21.21)
CVE-2026-3593 7.4 - High - May 20, 2026

A use-after-free vulnerability exists within the DNS-over-HTTPS implementation. This issue affects BIND 9 versions 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, and 9.20.9-S1 through 9.20.22-S1. BIND 9 versions 9.18.0 through 9.18.48 and 9.18.11-S1 through 9.18.48-S1 are NOT affected.

Dangling pointer

Amplified Resource Consumption in BIND 9 Resolvers (9.11-9.21.21)
CVE-2026-3592 5.3 - Medium - May 20, 2026

BIND resolvers are vulnerable to an amplified resource consumption/exhaustion attack. If a victim resolver makes a query to a specially crafted zone, the resolver will consume disproportionate resources. This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.48, 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1.

Incorrect Behavior Order: Early Amplification

BIND 9 TKEY GSS-API Excessive Mem (9.16.50/9.18.48/9.20.22/9.21.21)
CVE-2026-3039 7.5 - High - May 20, 2026

BIND servers that are configured to use TKEY-based authentication via GSS-API tokens are vulnerable to excessive memory consumption when receiving and processing maliciously-constructed packets. Typically these servers will be found in Active Directory integrated DNS deployments and/or Kerberos-secured DNS environments. This issue affects BIND 9 versions 9.0.0 through 9.16.50, 9.18.0 through 9.18.48, 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, 9.9.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1.

Missing Reference to Active Allocated Resource

Rsync <=3.4.3 TOCTOU Race Allows Arbitrary File Write/Privilege Escalation
CVE-2026-29518 7 - High - May 20, 2026

Rsync versions before 3.4.3 contain a time-of-check to time-of-use (TOCTOU) race condition in daemon file handling that allows attackers to redirect file writes outside intended directories by replacing parent directory components with symbolic links. Attackers with write access to a module path can exploit this race condition to create or overwrite arbitrary files, potentially modifying sensitive system files and achieving privilege escalation when the daemon runs with elevated privileges. This vulnerability can only be triggered if the chroot setting is false.

TOCTTOU

Unbound 1.141.25 UAF via RPZ XFR Reload Lock Inconsistency
CVE-2026-44608 - May 20, 2026

NLnet Labs Unbound 1.14.0 up to and including version 1.25.0 has a locking inconsistency vulnerability that when certain conditions are met (multi-threaded, RPZ XFR reload, RPZ zone with 'rpz-nsip'/'rpz-nsdname' triggers) it could result in heap use-after-free and eventual crash. An adversary can exploit the vulnerability if conditions are first met on a vulnerable Unbound, i.e., multi-threaded, an RPZ zone with 'rpz-nsip'/'rpz-nsdname' triggers and an ongoing XFR for that RPZ zone. Local RPZ files do not trigger the vulnerability. If the timing is right and an XFR happens at the same time another thread needs to read that RPZ zone, the reader may not hold the lock long enough and the thread applying the XFR may free objects that the reader is about to walk causing the use-after-free. Unbound 1.25.1 contains a patch with a fix to the locking code.

Improper Resource Locking

Unbound <=1.25.0 DoS via unbounded name compression on large RRsets
CVE-2026-44390 - May 20, 2026

NLnet Labs Unbound up to and including version 1.25.0 has a vulnerability when handling replies with very large RRsets that Unbound needs to perform name compression for. Malicious upstream responses with very large RRsets with records that don't share a suffix above the root can cause Unbound to spend a considerable time applying name compression to downstream replies. This can lead to degraded performance and eventually denial of service in well orchestrated attacks. An adversary can exploit the vulnerability by querying Unbound for the specially crafted contents of a malicious zone with very large RRsets. Before Unbound replies to the query it will try to apply name compression which was an unbounded operation that could lock the CPU until the whole packet was complete. A compression limit was introduced in 1.21.1 for this but it didn't account for the case where records would not share any suffix above the root. That causes Unbound to go in a different code path because of the compression tree lookup failure and eventually not increment the compression counter for those operations. Unbound 1.25.1 contains a patch with a fix that increments the compression counter regardless of the compression tree lookup. This is a complement fix to CVE-2024-8508.

Inefficient Algorithmic Complexity

Unbound<=1.25.0: DNS Cache Poison via Promiscuous Authority RRSets
CVE-2026-42960 - May 20, 2026

NLnet Labs Unbound up to and including version 1.25.0 is vulnerable to poisoning via promiscuous records for the authority section. Promiscuous RRSets that complement DNS replies in the authority section can be used to trick Unbound to cache such records. If an adversary is able to attach such records in a reply (i.e., spoofed packet, fragmentation attack) he would be able to poison Unbound's cache. A malicious actor can exploit the possible poisonous effect by injecting RRSets other than NS that are also accompanied by address records in a reply, for example MX. This could be achieved by trying to spoof a reply packet or fragmentation attacks. Unbound would then accept the relative address records in the additional section and cache them if the authority RRSet has enough trust at this point, i.e., in-zone data for the delegation point. Unbound 1.25.1 contains a patch with a fix that disregards address records from the additional section if they are not explicitly relevant only to authority NS records, mitigating the possible poison effect. This is a complement fix to CVE-2025-11411.

Acceptance of Extraneous Untrusted Data With Trusted Data

Unbound DNSSEC Validator DoS via Off-by-Counter in ADDITIONAL Section 1.25.0
CVE-2026-42959 - May 20, 2026

NLnet Labs Unbound up to and including version 1.25.0 has a denial of service vulnerability in the DNSSEC validator that can lead to a crash given malicious upstream replies. When Unbound constructs chase-reply messages for validation, the code uses the wrong counter to calculate write offsets for ADDITIONAL section rrsets. DNAME duplication could increase the ANSWER section count and authority filtering could decrease the AUTHORITY section count and create an uninitialized array slot. Combining these two, the validator later dereferences this uninitialized pointer, causing an immediate process crash. An adversary controlling a DNSSEC-signed domain can trigger this bug with a single query by configuring a DNAME chain with unsigned CNAMEs and a response containing unsigned AUTHORITY records alongside signed ADDITIONAL glue records. Unbound 1.25.1 contains a patch with a fix to use the proper counters to calculate the write offsets.

Access of Uninitialized Pointer

Unbound 1.14.01.25.0 Heap Overflow via EDNS Options
CVE-2026-42944 - May 20, 2026

NLnet Labs Unbound 1.14.0 up to and including version 1.25.0 has a vulnerability that results in heap overflow when encoding multiple NSID and/or DNS Cookie EDNS and/or EDNS Padding options in the reply packet. The relevant options ('nsid', 'answer-cookie', 'pad-responses' (default)) need to be enabled for the vulnerability to be exploited. An adversary who can query Unbound can exploit the vulnerability by attaching multiple NSID and/or DNS Cookie EDNS and/or EDNS Padding options to the query. A flaw in the size calculation of the EDNS field truncates the correct value which allows the encoder to overflow the available space when writing. Those two combined lead to a heap overflow write of Unbound controlled data and eventually a crash. Unbound 1.25.1 contains a patch with a fix to de-duplicate the EDNS options and a fix to prevent truncation of the EDNS field size calculation.

Numeric Truncation Error

DNSSEC Validator NSEC3 Hash Degrad DoS in Unbound <=1.25.0
CVE-2026-42923 - May 20, 2026

NLnet Labs Unbound up to and including version 1.25.0 has a vulnerability in the DNSSEC validator where the code path to consult the negative cache for DS records does not take into account the limit on NSEC3 hash calculations introduced in 1.19.1. This leads to degradation of service during the attack. An adversary that controls a DNSSEC signed zone can exploit this by signing NSEC3 records with acceptably high iterations for child delegations and querying a vulnerable Unbound. Unbound will keep performing the allowed hash calculations on the NSEC3 records and will not limit the work by the mitigation introduced in 1.19.1. As a side effect, a global lock for the negative cache will be held for the duration of the hashing, blocking other threads that need to consult the negative cache. Coordinated attacks could raise the vulnerability to denial of service. Unbound 1.25.1 contains a patch with a fix to bound the vulnerable code path with the existing limit for NSEC3 hash calculations.

Inefficient Algorithmic Complexity

Unbound 1.25.0 jostle logic flaw can degrade resolution performance
CVE-2026-42534 - May 20, 2026

NLnet Labs Unbound up to and including version 1.25.0 has a vulnerability in the jostle logic that could defeat its purpose and degrade resolution performance. Retransmits of the same query could renew the age of slow running queries and not allow the jostle logic to see them as aged and potential targets for replacement with new queries. An adversary who can query a vulnerable Unbound and who can control a domain name server that replies slowly and/or maliciously to Unbound's queries can exploit the vulnerability and degrade the resolution performance of Unbound. When Unbound's 'num-queries-per-thread' reaches its limit, the jostle logic kicks in. When a new query comes in, half of the available queries that are also slow to resolve are candidates for replacement. The vulnerability then happens because duplicate queries that need resolution would skew the aging result by using the timestamp of the latest duplicate query instead of the original one that started the resolution effort. Cache and local data response performance remains unaffected. Coordinated attacks could raise this to a denial of resolution service. Unbound 1.25.1 contains a patch with a fix to attach an initial, non-updatable start time for incoming queries that allow the jostle logic to work as intended.

Expected Behavior Violation

Unbound <1.25.1 DoS via Excess EDNS Options
CVE-2026-41292 - May 20, 2026

NLnet Labs Unbound up to and including version 1.25.0 is vulnerable to a degradation of service attack related to parsing long lists of incoming EDNS options. An adversary sending queries with too many EDNS options can hold Unbound threads hostage while they are parsing and creating internal data structures for the options. Coordinated attacks can result in degradation and/or denial of service. Unbound 1.25.1 contains a patch with a fix to limit acceptable incoming EDNS options (100).

Inefficient Algorithmic Complexity

Unbound <1.25.1 TTL Cache Abuse via Ghost Domains
CVE-2026-40622 - May 20, 2026

NLnet Labs Unbound 1.16.2 up to and including version 1.25.0 has a vulnerability of the 'ghost domain names' family of attacks that could extend the ghost domain window by up to one cached TTL configured value. Similar to other 'ghost domain names' attacks, an adversary needs to control a (ghost) zone and be able to query a vulnerable Unbound. A single client NS query can cause Unbound to overwrite the cached expired parent-side referral NS rrset with the child-side apex NS rrset and essentially extend the ghost domain window by up to one cached TTL configured value ('cache-max-ttl'). In configurations where 'harden-referral-path: yes' is used (non-default configuration), no client NS query is required since Unbound implicitly performs that query. Unbound 1.25.1 contains a patch with a fix that does not allow extension of TTLs for (parent) NS records regardless of their trust.

Origin Validation Error

Unbound DNSSEC deep-copy bug (CVE-2026-33278), fixed 1.25.1
CVE-2026-33278 - May 20, 2026

NLnet Labs Unbound 1.19.1 up to and including version 1.25.0 has a vulnerability in the DNSSEC validator that enables denial of service and possible remote code execution as a result of deep copying a data structure and erroneously overwriting a destination pointer. An adversary can exploit the vulnerability by controlling a malicious signed zone and querying a vulnerable Unbound. When DS sub-queries need to suspend validation due to NSEC3 computational budget exhaustion (introduced in Unbound 1.19.1), Unbound deep-copies response messages to preserve them across memory region teardown. A struct-assignment bug overwrites the destination's pointer with the source's pointer. After the sub-query region is freed, the resumed validator dereferences this dangling pointer, triggering a crash or potentially enabling arbitrary code execution. Unbound 1.25.1 contains a patch with a fix to preserve the correct pointer when deep copying the data structure.

Dangling pointer

Unbound <1.25.0 DNSCrypt denialofservice (heap overflow)
CVE-2026-32792 - May 20, 2026

NLnet Labs Unbound 1.6.2 up to and including version 1.25.0 has a denial of service vulnerability when compiled with DNSCrypt support ('--enable-dnscrypt'). A bad DNSCrypt query could underflow Unbound's DNSCrypt packet reading procedure that may lead to heap overflow. A malicious actor can exploit the vulnerability with a single bad DNSCrypt query that its decrypted plaintext consists entirely of '0x00' bytes and does not contain the expected '0x80' marker. Unbound would then start reading more bytes than necessary until it finds a non-'0x00' byte. Based on the underlying memory allocator and the memory layout, it could lead to heap overflow while reading followed by a crash. Likelihood of a crash is low, since it relies heavily on the underlying memory allocator and the memory layout. If the heap overflow does not happen, Unbound's later packet checks will deny the packet. Unbound 1.25.1 contains a patch with a fix to bound reading in the given buffer space.

Improper Handling of Missing Special Element

Rsync Hostname-based ACL bypass <3.4.3: Auth bypass via PTR
CVE-2026-43617 4.8 - Medium - May 20, 2026

Rsync version 3.4.2 and prior contain an authorization bypass vulnerability in the rsync daemon's hostname-based access control list enforcement when configured with chroot. Attackers can bypass hostname-based deny rules by controlling the PTR record for their source IP address, allowing connections from hostnames that administrators intended to deny when reverse DNS resolution fails and defaults to UNKNOWN.

Authentication Bypass by Alternate Name

Rsync 3.4.2 and earlier Integer Overflow in compressed-token decoder
CVE-2026-43618 8.1 - High - May 20, 2026

Rsync version 3.4.2 and prior contain an integer overflow vulnerability in the compressed-token decoder where a 32-bit signed counter is not checked for overflow, allowing a malicious sender to trigger an overflow that causes the receiver process to read and return data from outside the intended buffer bounds. Attackers can exploit this vulnerability to disclose process memory contents including environment variables, passwords, heap and stack data, and library memory pointers, significantly reducing ASLR effectiveness and facilitating further exploitation.

Integer Overflow or Wraparound

rsync 3.4.2 and earlier Symlink Race Condition in Path-based Syscalls
CVE-2026-43619 6.3 - Medium - May 20, 2026

Rsync version 3.4.2 and prior contain symlink race condition vulnerabilities in path-based system calls including chmod, lchown, utimes, rename, unlink, mkdir, symlink, mknod, link, rmdir, and lstat that allow local attackers to redirect operations to files outside the exported rsync module. Attackers with local filesystem access can exploit the timing window between path resolution and syscall execution by swapping symlinks to apply sender-supplied permissions, ownership, timestamps, or filenames to arbitrary files outside the intended module boundary on rsync daemons configured with 'use chroot = no'.

TOCTTOU

Rsync <3.4.3: Receiver-side OOB array read crash via CF_INC_RECURSE
CVE-2026-43620 6.5 - Medium - May 20, 2026

Rsync version 3.4.2 and prior contain a receiver-side out-of-bounds array read vulnerability in recv_files() in receiver.c that allows a malicious rsync server to crash the rsync client process. Attackers can exploit the vulnerability by setting CF_INC_RECURSE in compatibility flags and sending a specially crafted file list where the first sorted entry is not the leading dot directory, followed by a transfer record with ndx=0 and an iflag word without ITEM_TRANSFER, causing the receiver to read 8 bytes before the allocated pointer array and dereference an invalid pointer at an unmapped address, resulting in a deterministic SIGSEGV crash of the rsync client.

Out-of-bounds Read

Rsync <3.4.3: OOB stack write in establish_proxy_connection()
CVE-2026-45232 3.1 - Low - May 20, 2026

Rsync versions before 3.4.3 contain an off-by-one out-of-bounds stack write vulnerability in the establish_proxy_connection() function in socket.c that allows network attackers to corrupt stack memory by sending a malformed HTTP proxy response. Attackers can exploit this by positioning themselves between the client and proxy or controlling the proxy server to send a response line of 1023 or more bytes without a newline terminator, causing a null byte to be written to an out-of-bounds stack address when the RSYNC_PROXY environment variable is set.

off-by-five

GnuTLS DTLS DoS via Duplicate Seq Number Reordering
CVE-2026-42009 7.5 - High - May 18, 2026

A flaw was found in gnutls. A remote attacker could exploit an issue in the Datagram Transport Layer Security (DTLS) packet reordering logic. The comparator function, responsible for ordering DTLS packets by sequence numbers, did not correctly handle packets with duplicate sequence numbers. This could lead to unstable packet ordering or undefined behavior, resulting in a denial of service.

Undefined Behavior for Input to API

PostgreSQL <18.4,<17.10,<16.14: SQLi via ALTER SUBSCRIPTION REFRESH PUBLICATION
CVE-2026-6638 3.7 - Low - May 14, 2026

SQL injection in PostgreSQL logical replication ALTER SUBSCRIPTION ... REFRESH PUBLICATION allows a subscriber table creator to execute arbitrary SQL with the subscription's publication-side credentials. The attack takes effect at the next REFRESH PUBLICATION. Within major versions 16, 17, and 18, minor versions before PostgreSQL 18.4, 17.10, and 16.14 are affected. Versions before PostgreSQL 16 are unaffected.

SQL Injection

PostgreSQL refint stack buffer overflow, <= 18.4
CVE-2026-6637 8.8 - High - May 14, 2026

Stack buffer overflow in PostgreSQL module "refint" allows an unprivileged database user to execute arbitrary code as the operating system user running the database. A distinct attack is possible if the application declares a user-controlled column as a "refint" cascade primary key and facilitates user-controlled updates to that column. In that case, a SQL injection allows a primary key update value provider to execute arbitrary SQL as the database user performing the primary key update. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected.

Stack Overflow

PostgreSQL 18 Buffer Over-Read in pg_restore_attribute_stats() (18.3)
CVE-2026-6575 4.3 - Medium - May 14, 2026

Buffer over-read in PostgreSQL function pg_restore_attribute_stats() accepts array values of unmatched length, which causes query planning to read past end of one array. This allows a table maintainer to infer memory values past that array end. Within major version 18, minor versions before PostgreSQL 18.4 are affected. Versions before PostgreSQL 18 are unaffected.

Buffer Over-read

PostgreSQL Recursion CVE-2026-6479: SSL/GSS DoS pre-18.4,17.10,16.14,15.18,14.23
CVE-2026-6479 7.5 - High - May 14, 2026

Uncontrolled recursion in PostgreSQL SSL and GSS negotiation allows an attacker able to connect to a PostgreSQL AF_UNIX socket to achieve sustained denial of service. If SSL and GSS are both disabled, an attacker can do the same via access to a PostgreSQL TCP socket. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected.

Stack Exhaustion

PostgreSQL MD5 Timing Channel CVE-2026-6478 (v<18.4/17.10/16.14/15.18/14.23)
CVE-2026-6478 6.5 - Medium - May 14, 2026

Covert timing channel in comparison of MD5-hashed password in PostgreSQL authentication allows an attacker to recover user credentials sufficient to authenticate. This does not affect scram-sha-256 passwords, the default in all supported releases. However, current databases may have MD5-hashed passwords originating in upgrades from PostgreSQL 13 or earlier. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected.

Covert Timing Channel

PostgreSQL libpq PQfn buffer overflow in lo_* before 18.4, 17.10, 16.14, 15.18
CVE-2026-6477 8.8 - High - May 14, 2026

Use of inherently dangerous function PQfn(..., result_is_int=0, ...) in PostgreSQL libpq lo_export(), lo_read(), lo_lseek64(), and lo_tell64() functions allows the server superuser to overwrite a client stack buffer with an arbitrarily-large response. Like gets(), PQfn(..., result_is_int=0, ...) stores arbitrary-length, server-determined data into a buffer of unspecified size. Because both the \lo_export command in psql and pg_dump call lo_read(), the server superuser can overwrite pg_dump or psql stack memory. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected.

Use of Inherently Dangerous Function

PostgreSQL 17.x/18.x SQLi in pg_createsubscriber (17.9/18.3)
CVE-2026-6476 7.2 - High - May 14, 2026

SQL injection in PostgreSQL pg_createsubscriber allows an attacker with pg_create_subscription rights to execute arbitrary SQL as a superuser. The attack takes effect when pg_createsubscriber next runs. Within major versions 17 and 18, minor versions before PostgreSQL 18.4 and 17.10 are affected. Versions before PostgreSQL 17 are unaffected.

SQL Injection

PostgreSQL pg_basebackup/pg_rewind SYMLINK overwrite <=18.4/17.10/16.14/15.18/14.23
CVE-2026-6475 8.8 - High - May 14, 2026

Symlink following in PostgreSQL pg_basebackup plain format and in pg_rewind allows an origin superuser to overwrite local files, e.g. /var/lib/postgres/.bashrc, that hijack the operating system account. It will remain the case that starting the server after these commands implicitly trusts the origin superuser, due to features like shared_preload_libraries. Hence, the attack has practical implications only if one takes relevant action between these commands and server start, like moving the files to a different VM or snapshotting the VM. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected.

Symlink following

PostgreSQL timeofday() FS Vulnerability (pre-18.4,17.10,16.14,15.18,14.23)
CVE-2026-6474 4.3 - Medium - May 14, 2026

Externally-controlled format string in PostgreSQL timeofday() function allows an attacker to retrieve portions of server memory, via crafted timezone zones. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected.

Use of Externally-Controlled Format String

PostgreSQL <18.4 OOB Integer Wraparound Undersize Allocation
CVE-2026-6473 8.8 - High - May 14, 2026

Integer wraparound in multiple PostgreSQL server features allows an unprivileged database user to cause the server to undersize an allocation and write out-of-bounds. This may execute arbitrary code as the operating system user running the database. In applications that pass gigabyte-scale user inputs to the relevant database functions, the application input provider may achieve a segmentation fault. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected.

Integer Overflow or Wraparound

PostgreSQL 18.4+ Missing Auth in CREATE TYPE (search_path hijack)
CVE-2026-6472 5.4 - Medium - May 14, 2026

Missing authorization in PostgreSQL CREATE TYPE allows an object creator to hijack other queries that use search_path to find user-defined types, including extension-defined types. That is to say, the victim will execute arbitrary SQL functions of the attacker's choice. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected.

AuthZ

libcurl Proxy Digest Auth Header Leak on Handle Reuse
CVE-2026-7168 5.3 - Medium - May 13, 2026

Successfully using libcurl to do a transfer over a specific HTTP proxy (`proxyA`) with **Digest** authentication and then changing the proxy host to a second one (`proxyB`) for a second transfer, reusing the same handle, makes libcurl wrongly pass on the `Proxy-Authorization:` header field meant for `proxyA`, to `proxyB`.

CURL libcurl HTTP Redirect Password Leak via .netrc
CVE-2026-6429 5.3 - Medium - May 13, 2026

When asked to both use a `.netrc` file for credentials and to follow HTTP redirects, libcurl could leak the password used for the first host to the followed-to host under certain circumstances.

Stale Host Header Causes Cookie Leakage in libcurl
CVE-2026-6276 7.5 - High - May 13, 2026

Using libcurl, when a custom `Host:` header is first set for an HTTP request and a second request is subsequently done using the same *easy handle* but without the custom `Host:` header set, the second request would use stale information and pass on cookies meant for the first host in the second request. Leak them.

Curl Credential Leak via Proxy Chain Redirect
CVE-2026-6253 5.9 - Medium - May 13, 2026

curl might erroneously pass on credentials for a first proxy to a second proxy. This can happen when the following conditions are true: 1. curl is setup to use specific different proxies for different URL schemes 2. the first proxy needs credentials 3. the second proxy uses no credentials 4. while using the first proxy (using say `http://`), curl is asked to follow a redirect to a URL using another scheme (say `https://`), accessed using a second, different, proxy

libcurl SMB Connection Reuse flaw leads to wrong file transfer
CVE-2026-5773 7.5 - High - May 13, 2026

libcurl might in some circumstances reuse the wrong connection for SMB(S) transfers. 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 network transfer operation that was requested by an application could wrongfully reuse an existing SMB connection to the same server that was using a different 'share' than the new subsequent transfer should. This could in unlucky situations lead to the download of the wrong file or the upload of a file to the wrong place. When this happens, the same credentials are used and the server name is the same.

libcurl Auth Credential Leak via Connection Reuse
CVE-2026-5545 6.5 - Medium - May 13, 2026

libcurl might in some circumstances reuse the wrong connection when asked to do an authenticated HTTP(S) request after a Negotiate-authenticated one, when both use the same host. 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 credentials. An application that first uses Negotiate authentication to a server with `user1:password1` and then does another operation to the same server asking for any authentication method but for `user2:password2` (while the previous connection is still alive) - the second request gets confused and wrongly reuses the same connection and sends the new request over that connection thinking it uses a mix of user1's and user2's credentials when it is in fact still using the connection authenticated for user1...