CVE-2026-6637

-- PoC Concept for CVE-2026-6637 -- Scenario 1: SQL Injection via refint cascade primary key update -- The application updates a primary key column managed by the refint module based on user input. -- Malicious payload (SQL Injection) -- Value: '1; DROP TABLE sensitive_data; --' -- Vulnerable Query (Simulated) -- UPDATE users SET user_id = '1; DROP TABLE sensitive_data; --' WHERE user_id = 1; -- Scenario 2: Stack Buffer Overflow -- Sending a specially crafted long string to trigger the overflow in the refint module. -- Payload construction requires a specific length to overwrite the return address. -- Example (Conceptual): -- 'A' * 1000 + [Return Address]

{"cve": {"id": "CVE-2026-6637", "sourceIdentifier": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007", "published": "2026-05-14T14:16:25.820", "lastModified": "2026-05-14T16:21:23.190", "vulnStatus": "Undergoing Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "metrics": {"cvssMetricV31": [{"source": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-89"}, {"lang": "en", "value": "CWE-121"}]}], "references": [{"url": "https://www.postgresql.org/support/security/CVE-2026-6637/", "source": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007"}]}}