Firefox 1.5.0.4
Firefox 1.5.0.4 has been released to fix several security vulnerabilities which are discussed in US-CERT Cyber Security Alert SA06-153A also. The legacy setup can be downloaded over here, but of course I did a repackage for you in order to provide you a MSI package. Check out the "Download area" for the US version of Firefox 1.5.0.4.

