UBUNTU-CVE-2026-120651: Medium severity ubuntu/libcgi-pm-perl vulnerability

CGI versions before 5.00 for Perl allow an infinite loop on a short request body when $DISABLEUPLOADS is set. When $CGI::PUTDATAUPLOAD or an upload hook is set, readpostdataputdata takes a request body that is not a form submission. With $CGI::DISABLEUPLOADS set, it discards the body by reading until Content-Length bytes have arrived. Once a body shorter than its Content-Length runs out, every read returns 0, so the loop never ends. A client can keep a server process spinning with one such request.