Microsoft has just released a security advisory about a new zero-day vulnerability found in a bunch of versions of Word and Works:
Word 2000
Word 2002
Word 2003
Word Viewer 2003
Word 2004 for Mac
Word 2004 v. X for Mac
Works 2004
Works 2005
Works 2006
So far the use of this vulnerability is limited and we're monitoring the situation. Interestingly enough this vulnerability wasn't found the day after Microsoft's Patch-Tuesday which has been the case for most of the other Office vulnerabilities found during 2006. Let's just hope Microsoft can get this fixed in time for the next batch of monthly patches which is on the 12th of December.
In the meanwhile, we can all follow this useful workaround suggested by Microsoft: Do not open or save Word files that you receive from untrusted sources or that you receive unexpectedly from trusted sources.