CVE-2026-6479 PUBLISHED

PostgreSQL SSL/GSS init causes denial of service, via uncontrolled recursion

Assigner: PostgreSQL
Reserved: 17.04.2026 Published: 14.05.2026 Updated: 14.05.2026

Uncontrolled recursion in PostgreSQL SSL and GSS negotiation allows an attacker able to connect to a PostgreSQL AF_UNIX socket to achieve sustained denial of service. If SSL and GSS are both disabled, an attacker can do the same via access to a PostgreSQL TCP socket. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected.

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS Score: 7.5

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	None
Privileges Required	None	Integrity Impact	None
User Interaction	None	Availability Impact	High

CVSS 3.1

Product Status

Vendor	n/a
Product	PostgreSQL
Versions	Default: unaffected affected from 18 to 18.4 (excl.) affected from 17 to 17.10 (excl.) affected from 16 to 16.14 (excl.) affected from 15 to 15.18 (excl.) affected from 0 to 14.23 (excl.)

Workarounds

enable SSL and/or GSS; disable unix_socket_directories

Credits

The PostgreSQL project thanks Calif.io in collaboration with Claude and Anthropic Research for reporting this problem.

References

https://www.postgresql.org/support/security/CVE-2026-6479/

Problem Types

Uncontrolled Recursion CWE