Microsoft said Thursday it will release three security updates on this coming Patch Tuesday, including one that is rated "critical" and could allow an attacker to take over the computer.
The critical update affects Windows 2000, XP, Vista and Server 2003 and 2008, the company said in an advisory.
The other two updates are rated "important" and could be used for spoofing, in which an attacker is able to masquerade as someone else. One of the patches affects all supported versions of Windows and the second affects Windows 2000, Server 2003, and Server 2008.
Missing from the security updates is a fix for a security vulnerability in Excel, for which there have been Zero-Day exploits.