Two serious security flaws hit Microsoft Windows
 

EEYE DIGITAL SECURITY said it has discovered two critical security flaws which affect Windows XP, W2K, NT 4.0, and Windows Server 2003.
Microsoft will fix the problems in a November update.

The flaws affect Enanced Metafile and Windows Metafile and heap overflows in WMF. There's more details at the eEye web site and also at Microsoft's site.

http://theinquirer.net/?article=27551

http://www.microsoft.com/technet/sec.../MS05-053.mspx