Mozilla has released Firefox 3.5.1 to fix the recently reported security vulnerability in the Just-in-Time (JIT) JavaScript compiler, an exploit for the Windows version of which is already doing the rounds. Attackers can exploit the vulnerability to inject and execute code on vulnerable systems.

Mozilla Firefox 2.0.0.5 has been released and is currently being distributed to Firefox 2 users via the application's built-in software update system. The browser upgrade fixes several security bugs, which are detailed in the Firefox 2.0.0.5 section of the Mozilla Foundation Security Advisories page.

A security researcher has released zero-day code for a flaw in the Linux kernel, saying that it bypasses security protections in the operating system. The source code for the exploit was made available last week by researcher Brad Spengler on the Dailydave mailing list.

Microsoft released a security advisory to acknowledge a flaw that affects every release of the Windows NT kernel, from Windows NT 3.1 up to and including Windows 7.

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.

Version 3.6.2, which so far is only available as a beta, fixes a critical security hole in Firefox 3.6 for Windows that was discovered some time ago

The flaw discovered in Ralink's Wi-fi drivers for Windows last weekend also affects the Linux drivers – as already suspected. Attackers can exploit the hole to crash a computer remotely or possibly even inject and execute arbitrary code. Debian has released new packages for the rt2400, rt2500 and rt2570 models, but the packages need to be compiled by the user for the time being.

As announced, Mozilla has released the first update for Firefox 3.5, prompted by the disclosure of a critical security flaw related to TraceMonkey, the new JavaScript optimizer, earlier this week.

Firefox 3 developers are taking all the time that they need to accomplish their new Firefox. After the Beta 1 Mozilla has released Firefox 3 beta 2 to get more feedbacks about bugs from its testing community. Bugzilla was a little bit busy lately since the beta 1 thousands of bugs fortunately 900 of them are fixed. Firefox developers are trying to reveal more bugs to make their Firefox 3 better. The Beta 2 features are very promising and the Firefox 3 will definitely beat all competitors.