This update addresses three privately reported vulnerabilities and one publicly disclosed vulnerability. The security update addresses these vulnerabilities by modifying the way that Internet Explorer processes data stream headers, validates arguments, and handles objects in memory. For detailed information on the contents of this update, please see the following documentation:
This security update is rated Critical for all supported releases of Internet Explorer: Internet Explorer 5.01, Internet Explorer 6, Internet Explorer 6 Service Pack 1, Internet Explorer 7, and Internet Explorer 8.
As a reminder, IE security updates are cumulative and contain all previously released updates for each version of Internet Explorer.
I encourage everybody to download this security update and other non-IE security updates via Windows Update or Microsoft Update. Windows users are also strongly encouraged to configure their systems for automatic updates to keep their systems current with the latest updates from Microsoft.
Internet Explorer Security