IBM Db2 CVE-2026-1577

Attacker must possess valid Db2 database credentials (PR:L in CVSS vector confirms this requirement). No special database configuration or feature enablement is required; the flaw exists in the default query parsing logic. The attack is triggered by submitting a crafted SQL statement via any standard database connection method (SQL client, ODBC, JDBC, or application driver). However, database firewalls, VPN restrictions, or network segmentation limiting who can reach the database port will prevent remote exploitation even if credentials are compromised. Organizations with externally exposed Db2 ports face elevated risk; internal-only deployments are less critical.

CVSS 6.5 with network accessibility and low complexity indicates a moderate-severity denial of service with real operational impact. However, the mandatory authentication requirement (PR:L) significantly limits real-world risk: the attacker must possess valid database credentials, reducing the threat surface to trusted insiders or attackers who have compromised legitimate user accounts. EPSS data is unavailable, but SSVC framework assessment suggests availability impact only (A:H), no confidentiality or integrity breach. The absence of KEV listing and no public exploit confirmation indicate this is not currently being exploited at scale. For organizations with strong access controls and segregated database networks, this is a lower-priority patch; for environments with overly permissive database access, remediation becomes urgent.

An authenticated application user or database administrator with moderate privileges submits a specially crafted SQL query containing unfiltered special characters or malformed syntax to the Db2 parser. The query parser fails to properly neutralize these elements, triggering an unhandled exception or resource exhaustion that crashes the Db2 process. The database service becomes unavailable to all users until manual restart.