Based on the link you posted there is no patch available for this yet:
The Fix it is an effort to help protect as many customers as possible, as quickly as possible. We continue to work on a security update to address this issue and we’re closely monitoring the threat landscape.
You can download the FixIt utility that MS has provided and run that via a Managed Software Delivery policy against all of your XP w/IE8 computer to mitigate the flaw until the patch is actually released.