Mozilla introduced Firefox 3.6.2 to repair vital safety hole involving Web depending font technology. "We powerfully suggest that all Firefox users upgrade to this new release. If you have Firefox 3.6 you get automatic update notification in 24 to 48 hours. This update also applied you by choosing 'Check for Updates...' from Help menu," said Mozilla's director of Firefox, Mike Beltzner.

With vulnerability, attacker stop working person's browser and, poorer, run random code on machine, Mozilla said. As it involves Web Open Font Format (WOFF) technology introduced in Firefox 3.6, it doesn't change previous versions.