(http://news.zdnet.co.uk/security/0,1000000189,39286055,00.htm) has published a warning of a new and very dangerous security flaw in the new consumer version of Office 2007.
This is a file format problem discovered by eEye Security.
The threat was disclosed to Microsoft by eEye on February 16.
There are no details in the eEye Research posting except that this is a remote code execution threat in Publisher 2007.
In case you aren't keeping track, Office 2007 has only been shipping for a few weeks.
(I'm surprised it took this long to find a major vulnerability!)