Mozilla has released the fifth (there was no Firefox 3.6.1 or 3.6.5) update for Firefox 3.6.7 on July 20. This update included 126 bug fixes, this release patches 14 security vulnerabilities, 8 labeled as critical.

Users should be prompted soon to update, but can obtain this update via Help the Menu and selecting Check For Updates…For complete list of changes and more information, please see the Firefox 3.6.7 Release Notes.

Source: Mozilla Links