Catalyst::Plugin::Session before version 0.44 for Perl generates session ids insecurely.

The session id is generated from a (usually SHA-1) hash of a simple counter, the epoch time, the built-in rand function, the PID and the current Catalyst context. This information is of low entropy. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage.

Predicable session ids could allow an attacker to gain access to systems.

References

• https://nvd.nist.gov/vuln/detail/CVE-2025-40924
• perl-catalyst/Catalyst-Plugin-Session#5
• https://github.com/perl-catalyst/Catalyst-Plugin-Session/commit/c0e2b4ab1e42ebce1008286db8c571b6ee98c22c.patch
• https://metacpan.org/release/HAARG/Catalyst-Plugin-Session-0.43/source/lib/Catalyst/Plugin/Session.pm#L632