It's Patch Day in the land of Web browsers.
In separate warnings, Apple and Mozilla confirmed -- and fixed -- critical vulnerabilities affecting users of the Safari and Mozilla browsers.
The Apple Safari patch (available for Windows and Mac OS X), provides cover for at least four vulnerabilities (including Charlie Miller's winning CanSecWest contest exploit).
Here's the skinny on Firefox 18.104.22.168:
Also see this Bugzilla entry for technical details.