14 DAY TRIAL // The reason that caused this chemspill is a security issue, which, at the moment, remains undisclosed. However, it looks like it’s serious stuff, since the vulnerability was present in all builds and versions of Mozilla's web browser as well as Thunderbird email client.
And they really mean every build and version of the two products, starting with Firefox 3.6, beta builds, extended support releases (ESR) and all active Thunderbird releases.
Mobile versions of Firefox are also affected, as the update to 10.0.2 has also been released today on Android Market.
Firefox for Windows is available for download from this page Firefox for Mac is available for download from this page Firefox for Linux is available for download from this page Firefox for Android is available for download from this page