CVE-2026-14671 in PostgreSQL
Summary
by MITRE • 08/13/2026
Type confusion in PostgreSQL module "refint" allows an object creator to execute arbitrary code as the operating system user running the database. The fix for this emerged as a non-security bug report, and the fix appear in the git repository with subject "refint: Remove plan cache.", without a CVE number. 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 type confusion issue within PostgreSQL's reference integrity module known as "refint" which operates under the common weakness enumeration CWE-466. The flaw enables malicious object creators to execute arbitrary code with the privileges of the operating system user who runs the database service, creating a severe privilege escalation vector that can compromise entire database systems. The vulnerability specifically manifests in PostgreSQL versions prior to 18.5, 17.11, 16.15, 15.19, and 14.24 where improper type handling during query plan caching leads to memory corruption conditions.
The technical root cause stems from how the refint module manages query execution plans within PostgreSQL's query optimizer. When processing reference integrity constraints, the system caches execution plans for performance optimization purposes, but this caching mechanism fails to properly validate data types during plan reuse operations. This type confusion allows attackers to craft specially crafted database objects or queries that manipulate the cached plan structure, ultimately enabling code execution through memory corruption techniques. The vulnerability operates at the intersection of several attack vectors defined in the ATT&CK framework under T1059.001 for command and scripting interpreter and T1068 for exploit for privilege escalation.
The operational impact of this vulnerability extends beyond simple data compromise, as it provides attackers with direct system-level access through the database user context. Since PostgreSQL typically runs with elevated privileges to manage database operations, successful exploitation can lead to complete system compromise including potential lateral movement within network environments where database servers reside. The fact that the fix emerged from a non-security bug report rather than a formal vulnerability disclosure highlights the subtle nature of type confusion flaws which often masquerade as performance or stability issues before being recognized as security threats.
Database administrators should immediately implement mitigation strategies including applying the patched versions mentioned in the advisory, implementing strict access controls to limit object creation privileges, and monitoring for unusual query patterns that might indicate exploitation attempts. The fix itself addresses the core issue by removing the problematic plan cache mechanism within the refint module, effectively eliminating the type confusion vector. Organizations should also consider implementing database activity monitoring solutions to detect anomalous behavior patterns and establish robust patch management procedures to ensure timely deployment of security updates across all PostgreSQL installations in their environment.