Mozilla released an emergency update for Firefox users on Thursday, February 13th. Firefox 27.0.1 included two JavaScript (JS) related fixes (see below). Depending on update settings, users should automatically be prompted to update to Firefox 27 or may do so manually via Help > About Firefox or downloading and installing via the getfirefox.com site. The next scheduled released is Firefox 28 on March 18th, 2014. Fixed stability issues with Greasemonkey and other JS that used ClearTimeoutOrInterval JS math correctness issue (bug 941381)