Microsoft has released an Internet Explorer 7 security update for Windows Vista and Windows Server 2008

Security issues have been identified that could allow an attacker to compromise a computer running Microsoft Internet Explorer and gain control over it. You can help protect your computer by installing this update from Microsoft. After you install this item, you may have to restart your computer.

Cumulative Security Update for Internet Explorer 7 in Windows Server 2008 x64 Edition (KB2699988)
Cumulative Security Update for Internet Explorer 7 in Windows Vista x64 Edition (KB2699988)
Cumulative Security Update for Internet Explorer 7 in Windows Server 2008 (KB2699988)
Cumulative Security Update for Internet Explorer 7 in Windows Vista (KB2699988)
Cumulative Security Update for Internet Explorer 7 in Windows Server 2008 for Itanium-based Systems (KB2699988)