Uncaught exceptions in PostgreSQL plperl allow an object creator to cause use of a stale sigjmp_buf, via a tied Perl object, or a Perl object whose overloaded conversion throws while plperl is handling another error. We have not ruled out arbitrary code execution on some platform. Versions before PostgreSQL 18.7, 17.12, 16.16, 15.20, and 14.25 are affected.