CVE-2026-118993

CallBackery versions before 0.62.0 for Perl allow denial of service via the request path interpolated as a regular expression under CGI, FastCGI and PSGI.

The before dispatch hook installed by startup() removes PATH INFO from the end of the request URI with a substitution that interpolates PATH INFO unquoted. Under CGI, FastCGI and PSGI both values come from the request, so the client chooses both the pattern and the string it is matched against.

A short unauthenticated request with a backreference in the path backtracks exponentially and can keep a worker process busy for minutes.