Mozilla has release an update to Firefox 3.6 on November 8, 2011. Version 3.6.24 is a minor security and stability update for the Firefox 3.6/Gecko 1.9.2 branch. Users on Firefox 3.6.23 who are able to move to newer versions of Firefox (Firefox 5+) can not update to Firefox 3.6.24 automatically. Only users, who’s computers do not support the newer Firefox versions will be able to update automatically to the 3.6.24 release. However, users can manually update by going to the Firefox 3.6.24 download page and selecting the language and OS they wish to install. DO NOT click the latest version of Firefox link at the top as this will take you to the download for Firefox 8.0 version.
Unless there is a Firedrill release, the next version will be Firefox 3.6.25 set for release on December 20, 2011.