CVE-2026-6637
CWE-89Published: May 14, 2026· Updated: May 18, 2026
Official Description
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.
Technical Analysis
CVE-2026-6637 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 8.8.
From a weakness classification perspective (CWE-89): SQL injection vulnerabilities allow attackers to manipulate database queries, potentially exposing or modifying sensitive data.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (1)
Quick Facts
Related CVEs (CWE-89)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-6637 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts