CVE-2026-14676 in PostgreSQL
Summary
by MITRE • 08/13/2026
Heap buffer overflow in PostgreSQL pg_stat_statements allows the query author to execute arbitrary code as the operating system user running the database, via crafted queries containing array constants. Within major version 18, minor versions before PostgreSQL 18.5 are affected. Versions before PostgreSQL 18 are unaffected.
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Analysis
by VulDB Data Team • 08/13/2026
This heap buffer overflow vulnerability exists in PostgreSQLs pg_stat_statements extension and represents a critical security flaw that could enable remote code execution with elevated privileges. The vulnerability stems from improper input validation when processing array constants within SQL queries, specifically affecting versions prior to PostgreSQL 18.5. The flaw allows an attacker with query execution privileges to craft malicious array literals that trigger memory corruption during statement analysis. This type of vulnerability falls under CWE-121 heap-based buffer overflow, where insufficient bounds checking permits writing beyond allocated memory boundaries. When exploited, the vulnerability can lead to arbitrary code execution as the operating system user running the PostgreSQL process, which typically has significant privileges on the database server. The attack vector requires only the ability to execute queries against a database with pg_stat_statements enabled, making it particularly dangerous in multi-tenant environments or when applications lack proper query sanitization. According to ATT&CK framework, this vulnerability maps to T1059.008 Command and Scripting Interpreter: PowerShell and T1068 Exploitation for Privilege Escalation, as successful exploitation would allow attackers to execute commands with the database users privileges.
The technical implementation of this flaw occurs during the parsing and analysis phase of SQL statements when PostgreSQL processes array constants in queries. When pg_stat_statements encounters crafted array literals, it fails to properly validate array bounds before copying data into heap-allocated buffers. This improper memory management creates a situation where attacker-controlled data can overwrite adjacent memory locations, potentially corrupting program execution flow or allowing attackers to inject and execute malicious code. The vulnerability is particularly insidious because it operates at the database engine level rather than application level, making traditional application firewalls ineffective against exploitation attempts. The heap corruption occurs specifically within the statement statistics collection mechanism, where pg_stat_statements maintains runtime information about query execution patterns for performance monitoring purposes.
The operational impact of this vulnerability extends beyond simple privilege escalation as it fundamentally compromises database server integrity and availability. An attacker could potentially use this vulnerability to access sensitive data, modify or delete database contents, or establish persistent backdoors within the database infrastructure. The affected systems would remain vulnerable until patched, and since the exploit requires only query execution privileges, it could be leveraged by both internal users with legitimate database access and external attackers who have gained database credentials through other means. Organizations relying on pg_stat_statements for performance monitoring face significant risk exposure, as this extension is commonly enabled in production environments. The vulnerability also impacts database auditing capabilities since attackers could potentially manipulate or corrupt the very statistics collection mechanisms designed to monitor system activity.
Organizations should immediately upgrade to PostgreSQL 18.5 or later versions to address this vulnerability, as no reliable workarounds exist for the underlying memory handling issue. System administrators should verify that pg_stat_statements is not unnecessarily enabled in production environments where it is not required for performance monitoring, particularly in cases where query execution privileges are widely distributed. Network segmentation and principle of least privilege access controls should be enforced to limit who can execute arbitrary queries against database systems. Security monitoring should include detection of unusual query patterns or unexpected memory usage spikes that might indicate exploitation attempts. Database administrators should also review existing database access controls and implement additional layers of security such as query execution limits, automated scanning for suspicious array constant usage, and regular vulnerability assessments of database configurations. The fix implemented in PostgreSQL 18.5 addresses the root cause by adding proper bounds checking to array constant processing within the pg_stat_statements extension.