Thanks Snakefoot. Microsoft have released 3 patches for their Windows products:

Cumulative Patch for Internet Explorer (For all Windows versions)
http://www.microsoft.com/technet/security/bulletin/MS03-049.asp

Buffer Overrun in the Workstation Service (For Win2k/WinXP)
http://www.microsoft.com/technet/security/bulletin/MS03-049.asp

Certification Spoofing (For Win2k with IE6 SP1)
http://www.microsoft.com/technet/security/bulletin/MS02-050.asp

Quick overview of November fixes:
http://www.microsoft.com/security/security_bulletins/20031111_windows.asp