From ZDNET – Microsoft warns of 22 new security flaws:

“The other major class of flaws are those that affect applications on desktop computers, such as Internet Explorer and Excel. Threats to so-called client-side applications have been growing, Friedrichs said.

Of the current crop of vulnerabilities, 12 fall into that category. Of these, Microsoft rated five critical: three of the eight vulnerabilities in Internet Explorer, as well as two flaws in Excel.”

This Secunia article has the links to the Office/Excel Patches.