CVE-2026-6470: Missing Authorization

Missing authorization in PostgreSQL DDL commands allows an object creator to achieve denial of service against ALTER and DROP of the type, via creating a dependency on the type. Many DDL operations did check the privilege, but assigning a range subtype and referencing the type from an SQL expression did not. Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected.