Sure, it's nearly Thanksgiving, but Apple hasn't let everyone in Cupertino take the week off for turkey brining. No, the company's hard-at-work developers have issued OS X Mountain Lion 10.8.2 Supplemental Update 2.0 to Mac users. This update is recommended for all Mac systems introduced in 2012; it may not show up if you're using an older Mac.
Apple says that Supplemental Update 2.0 "addresses an issue with Keychain that can affect 2012 Mac systems."
The update is available in the Mac App Store--if you're using an eligible Mac--or directly from Apple's website. It weighs in at a dainty 26.65MB.