Catalyst::Plugin::Authentication versions before 0.10_027 for Perl is susceptible to session fixation attacks. Catalyst::Plugin::Authentication does not automatically change the session id after authentication. An attacker that obtains a session id cookie can use this to impersonate the victim.

Catalyst::Plugin::Authentication versions through 0.10024 for Perl is susceptible to timing attacks. These versions use Perl's built-in eq comparison. Discrepencies in timing could be used to guess the underlying hash or password.