"Firefox 1.0.5 is a security update that is part of our ongoing program to provide a safe Internet experience for our customers. We recommend that all users upgrade to this latest version," the Foundation stated in the browser's release notes.
Although Firefox is generally available in a large number of languages, version 1.0.5 is currently only available in English. The new version is shortly expected to be available in other languages.
A similar situation exists for different architectures; 1.0.5 is currently only being provided for the Windows, Mac OS X and Linux platforms, although unofficially supported builds for OS/2 and Solaris are likely to be released at some point.
As of this morning (AEST), The Mozilla Foundation had not updated its security page to reflect which particular vulnerabilities have been fixed. The change was expected to be made shortly.