Five of this week's nine Windows updates are critical. The Office Web Components vulnerability has been exploited for a couple months, and there are five ActiveX Controls that have been targeted by Bad Guys, and are not fixed. You'll want this update.
Run Windows Update and do a reboot, and you'll be up to scratch.
Apple has finally patched the bug-from-hell in bind, the DNS program that maps geeky numeric IP addresses to cool names like borepatch.blogspot.com. Plus a half dozen vulnerabilities in the Safari Web browser. Windows users of Safari will want that fix, too.
Linux users have your automatic updates from Ubuntu, so everything's copacetic, right? Right!