Everybody's favorite cat, OS X Mountain Lion, has a new update this morning. But don't be surprised if you don't see it under the Updates tab in the Mac App Store -- OS X Mountain Lion 10.8.2 Supplemental Update 2.0 is "recommended for all Mac systems introduced in 2012."
According to the update notes, the update "addresses an issue with Keychain that can affect 2012 Mac systems." The update file is relatively small, only about 26.65 MB in size.
OS X Mountain Lion Supplemental Update 2.0 fixes keychain errors originally appeared on