Mozilla is updating its Firefox 3.x browser to version 3.0.12 for five critical security vulnerabilities. All of the issues have already been addressed in the latest Firefox 3.5.1 update which came out last week.

Mozilla has released updates for its Thunderbird email client, the SeaMonkey "all-in-one internet application suite" and older versions of its Firefox web browser - addressing a number of critical security vulnerabilities

Mozilla recommends its updated Firefox 3.0.12 version for its new 3.0 series in that it removes a few critical security issues.

In an interesting twist on browser-based security issues, security researchers said they have found a flaw in which Microsoft's Internet Explorer can cause Mozilla's Firefox to execute remote malicious code. Security firm Secunia released an advisory Tuesday, ranking the flaw as highly critical. The vulnerability is confirmed on Firefox 2.0.0.4 on a fully-patched version of Windows XP SP2.

Mozilla has had a tough week. Yesterday they fixed a security problem in Thunderbird by releasing version 1.5.0.12 late yesterday. This followed on the heels of updates to Firefox, to a Firefox Google toolbar extension, and to the SeaMonkey web application suite -- all within the last six days.

Mozilla is out with the first update of 2010 to its open source Firefox Web browser. Unlike its immediate predecessor, Firefox 3.5.7 is not being issued to fix security issues, but rather is an update for a trio of stability-related bugs.

Mozilla is out this week with Firefox 3.5.9 and 3.0.19 updates, fixing multiple security vulnerabilities in the open source Web browser's two branches, while announcing that the older of the two branches is being phased out.

Mozilla's Firefox 3.5.1 browser is now out with fixes for one critical zero-day vulnerability that first became public earlier this week.

Mozilla has pushed out a new version of Firefox that fixes a number of security bugs, including a high-profile bug involving launching Firefox from Internet Explorer.