The Mozilla Foundation just released Firefox 3.5.4 – the new version closes 11 security holes of which 6 are considered critical from the Mozilla developers. Those vulnerabilities can be abused by cybercriminals to inject malicious code like a Trojan into the computer. The release also fixes a few non-security related issues.
Some of the bugs also affect earlier versions of the Mozilla browsers and get fixed within Firefox 3.0.15 (though it is recommended to update to Firefox 3.5) and in SeaMonkey 2.0. Thunderbird doesn’t get mentioned in the security advisories.
As some of the vulnerabilities are quite serious security issues, users should update the software as soon as possible. The easiest way is to go to the “Help” menu and choose “Check for Updates”.