Remember the Pwn2Own competition in which Chrome was the only browser left standing? Well, Firefox — along with almost every other popular browser — was exploited on the first day. Today, the folks at Mozilla pushed out a security update to 3.6.3 addressing the security vulnerability that the hacker exploited in the Pwn2Own competition.
You can either wait for an automatic update, force Firefox to check for updates, or head straight to the download page to grab the latest. However you do it, it's a good idea to update. [Mozilla Links]