Actually, as a Firefox user, the update was offered automatically with very little interaction on my part whatsoever.

The Mozilla Foundation has released an updated version of Firefox following the discovery of multiple security vulnerabilities involving the popular browser software.

The flaws create a means for hackers to conduct cross-site scripting or to otherwise seize control of vulnerable systems.

Many of the bugs involved the handling of JavaScript code while others involve memory corruption errors, as explained in a run-down by security notification firm Secunia here, that contains links to the relevant Mozilla Foundation advisories…. Source: The Register