The latest fixes 22 security flaws, in seven “Security Bulletins”, of which 3 are rated “Critical” and 4 are rated “Important”.

Most of these address remote code execution (RCE) (unfortunately not executing those responsible). RCE allows take over of your computer by a hacker acting from a distance.

Good news, none of these flaws have been exploited yet. The biggest flaws are in MSO 2003, 2007 and MSO for Mac 2011 and had to do with the way Rich Text is handled.

I strongly urge users of MSO for Mac 2011 to update their systems as well since security flaw exploitation for Mac OS is the up and coming thing.

MS also issued fixes to prevent Duqu malware from infecting Windows machines through .NET and Silverlight.

A remote flaw in Visio was also fixed.

So… I did all the updates, and no problems (W7 Home Premium, x64) were encountered.

Source:

http://www.infopackets.com/news/business/microsoft/2012/20120509_microsoft_fixes_critical_bugs_in_windows_office.htm