PostgreSQL -- Memory disclosure in partitioned-table UPDATE ... RETURNING

The PostgreSQL project reports:

    Using an UPDATE ... RETURNING on a purpose-crafted partitioned
    table, an attacker can read arbitrary bytes of server memory. In the
    default configuration, any authenticated database user can create
    prerequisite objects and complete this attack at will. A user
    lacking the CREATE and TEMPORARY privileges on all databases and the
    CREATE privilege on all schemas typically cannot use this attack at
    will.