Drupal 6.13 and 5.19 released
From the Drupal.org website:
Drupal 6.13 and 5.19, maintenance releases fixing problems reported using the bug tracking system, as well as critical security vulnerabilities, are now available for download. Both releases fix some other smaller issues as well.
Upgrading your existing Drupal 5 and 6 sites is strongly recommended.
Do the right thing! Stay up to date!