CVE-2026-14677 in PostgreSQL
Summary
by MITRE • 08/13/2026
Integer wraparound in PostgreSQL 32-bit builds of pltcl and plperl allows an object creator to cause the server to undersize an allocation and write out-of-bounds via crafted function bodies. This may execute arbitrary code as the operating system user running the database. CVE-2026-6473 had fixed similar problems. Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected.
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Analysis
by VulDB Data Team • 08/13/2026
This vulnerability represents a critical integer wraparound flaw affecting PostgreSQL's procedural language extensions pltcl and plperl in 32-bit builds. The issue stems from improper handling of integer arithmetic during memory allocation calculations, where developers failed to account for potential overflow conditions that could result in significantly smaller memory allocations than intended. When an object creator submits crafted function bodies containing maliciously constructed parameters, the system processes these inputs through the procedural language interpreters without adequate bounds checking. The vulnerability specifically targets the memory allocation routines within the interpreter code where integer values representing buffer sizes undergo arithmetic operations that can overflow and wrap around to small positive values or zero, leading to insufficient memory allocation for subsequent operations.
The technical execution of this vulnerability occurs when PostgreSQL processes user-defined functions written in Tcl or Perl through the respective procedural language extensions. During function compilation and execution, the system calculates required memory buffers based on input parameters and other dynamic factors. In 32-bit environments where integer overflow is more likely to occur due to limited address space, these calculations can produce wraparound conditions that result in allocations of only a few bytes instead of the intended large buffer sizes. When subsequent code attempts to write data beyond this artificially small allocation, it triggers out-of-bounds memory writes that can overwrite adjacent memory regions including function pointers, return addresses, or other critical program state information.
The operational impact of this vulnerability is severe as it enables remote code execution with the privileges of the database service account running on the system. Attackers who can create objects within a PostgreSQL database can exploit this flaw to execute arbitrary code on the server hosting the database, potentially leading to full system compromise. The vulnerability affects all versions prior to PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24, making it particularly concerning given that many organizations may be running older PostgreSQL installations. This issue is classified under CWE-190 as an integer overflow error and aligns with ATT&CK technique T1059.007 for execution through scripting languages, while also representing a privilege escalation vector through the database service account compromise.
The remediation strategy focuses on upgrading to the patched PostgreSQL versions that contain proper integer overflow checks and bounds validation in memory allocation routines. Database administrators should immediately apply the relevant security patches and verify that all 32-bit installations have been updated to prevent exploitation. Additional mitigations include restricting object creation privileges to trusted users only, disabling unnecessary procedural language extensions when not required for operations, and implementing network segmentation to limit exposure of database systems to untrusted networks. Organizations should also conduct thorough vulnerability assessments to identify any existing installations running affected versions and ensure that proper access controls are in place to prevent unauthorized users from creating malicious objects within the database environment.