This site tracks bugs in every distribution released through CPAN.
To report bugs in perl itself, you're best off using the command-line 'perlbug' tool or rt.perl.org.
This site lets you search for distributions by name or author. When you've found the distribution you're looking for, you can browse known bugs and report new bugs.
To work with bugs, every module author with a PAUSE account can log into rt.cpan.org with their PAUSE userid and password. If you can't log in or distributions you maintain aren't listed, please write to rt-cpan-admin@bestpractical.com at your earliest convenience.
If you have any questions about rt.cpan.org, feel free to send mail to rt-cpan-admin@bestpractical.com and we'll do our best to get back to you.
To submit a bug report for a given distribution by email, send mail to bug-<distribution-name>@rt.cpan.org, where "<distribution-name>" is something like DBIx-SearchBuilder or Class-DBI or Acme-Current-Forever.
Enjoy,
Jesse Vincent
Best Practical Solutions, LLC