Mozilla has released Firefox version 15.0 which fixes a number of critical security issues including potential memory corruption. All Firefox users should apply the update as soon as possible.
Note that this version of Firefox introduces silent updates, which allows the application to automatically update to newer versions.
For more information, see:
For Firefox ESR admins, the equivalent release is Firefox 10.0.7esr. See http://www.mozilla.org/en-US/firefox/organizations/ for more information.