CVE-2026-16239 PostgreSQL type confusion in cursor CLOSE + DECLARE executes arbitrary code

Type confusion in PostgreSQL "portal"/cursor lifecycle allows a user to execute arbitrary code as the operating system user running the database, via re-creation of a cursor or other portal with different types. Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected...