CVE-2026-14662 in PostgreSQL
Summary
by MITRE • 08/13/2026
Integer wraparound in PostgreSQL tsvector and tsquery data type functions allows an unprivileged database user to cause the server to undersize an allocation and write out-of-bounds, via crafted large inputs. This may execute arbitrary code as the operating system user running the database. These types are typically sourced from application logic, not taken from the application's user. Hence, application users attacking the database, through the application as a conduit, are unlikely. 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 in PostgreSQL's text search functionality that affects the tsvector and tsquery data types. The issue stems from improper handling of large input values during memory allocation calculations, where integer overflow conditions cause the system to allocate insufficient memory buffers. When crafted malicious inputs exceed normal processing limits, the integer arithmetic wraps around to produce unexpectedly small allocation sizes, creating buffer underflows that can be exploited for out-of-bounds memory writes. This class of vulnerability maps directly to CWE-190, which specifically addresses integer overflow and underflow conditions, and falls under the broader category of memory safety issues that have historically enabled arbitrary code execution exploits.
The technical implementation of this vulnerability involves PostgreSQL's internal text search processing functions that handle tokenization and query parsing operations. When processing large tsvector or tsquery inputs, the system performs mathematical calculations to determine buffer sizes needed for various internal data structures. Under normal circumstances these calculations should produce reasonable memory allocation requests, but integer wraparound occurs when input values exceed certain thresholds, causing the allocation size calculation to produce a value that is orders of magnitude smaller than required. This creates writable memory regions that can be manipulated to overwrite adjacent memory locations, potentially leading to code execution with the privileges of the database service account.
The operational impact of this vulnerability extends beyond traditional database security boundaries, as it provides a path for privilege escalation attacks. While the initial exploitation requires an unprivileged database user to craft malicious inputs that can trigger the integer wraparound condition, successful exploitation allows execution of arbitrary code at the operating system level with the same privileges as the PostgreSQL service. This means that attackers could potentially access sensitive data, modify database contents, or even establish persistent access through the database server. The vulnerability is particularly concerning because text search functionality is commonly used throughout applications for full-text indexing and searching capabilities, making it a frequent target for exploitation.
The fix implemented in PostgreSQL versions 18.5, 17.11, 16.15, 15.19, and 14.24 addresses the root cause by implementing proper integer overflow checks before memory allocation operations. These patches ensure that input validation occurs prior to any arithmetic calculations that determine buffer sizes, preventing the wraparound conditions that previously led to undersized allocations. The remediation follows established security practices for handling integer operations and aligns with ATT&CK technique T1059.007 for command and script injection, as the vulnerability could enable attackers to execute arbitrary commands through database interactions. Organizations should prioritize patching affected systems, especially those running older PostgreSQL versions that remain vulnerable to this specific class of memory corruption exploit.
This vulnerability demonstrates how seemingly innocuous database functions can become attack vectors when proper input validation and integer handling are not implemented. The historical context shows that similar issues have been addressed in previous CVE-2026-6473 patches, indicating a pattern in PostgreSQL's text search implementation that requires ongoing vigilance. The fact that these data types are typically sourced from application logic rather than direct user input means that applications must implement proper sanitization and validation of text search parameters before passing them to database functions, as the vulnerability can be exploited through application interfaces that process user-supplied content.