Microsoft today released its normal monthly batch of security fixes. This month, there are eleven patches for Windows and its components, and one each for Microsoft Office and Outlook. (As far as I can tell, these patches affect only the Windows versions of Office,) Microsoft assigns a maximum severity rating of Critical to four of these patches, and Important to the rest. More detail is available in the Security Bulletin Summary for September. (A breakdown of patch severity by Windows version is in my preview post for this month.)
All of these patches should be available from Windows Update; alternatively, there are download links in the Security Bulletin Summary.
The SANS Internet Storm Center has posted their usual monthly summary of the released patches.
I recommend installing these patches as soon as you conveniently can.