Heap buffer overflow in PostgreSQL to_char(timestamptz) allows a party that can choose the timezone to trigger memory corruption and execute arbitrary code as the OS user running the DB by supplying a long POSIX timezone abbreviation. Affects PostgreSQL < 18.5, < 17.11, < 16.15, < 15.19, < 14.24. Upgrade to 18.5/17.11/16.15/15.19/14.24 or later.