Update: A reader tells us "After installing the updates from Microsoft, each of the programs wanted me to re-enter a product key as though I never entered one many months ago." He confirmed this as an issue according to a Microsoft support call, although we don't know how many people it might affect.
Microsoft today announced the availability of the Office for Mac 2011 14.2.2 Update. According to Microsoft, "this update fixes extremely important issues and also helps improve security. It includes fixes for vulnerabilities that an attacker can use to overwrite the contents of your computer's memory with malicious code."
This is a rollup patch, meaning that it includes all of the improvements released in previous Office 2011 updates since the 14.1.0 update. To install the update, you must be running Mac OS X 10.5.8 or later and have previously installed the Office 2011 for Mac 14.1 update. Office users can verify that the previous update is in place by opening any Office application and checking the "About" dialog box.
The update should appear if you're running Microsoft AutoUpdate, or it can be downloaded directly from Microsoft.