Microsoft will today release an unscheduled patch to block a vulnerability in Internet Explorer 6 and 7.

Internet Explorer 8 is unaffected by the vulnerability, which only affects the earlier version of the browser and is detailed in Microsoft's Security Advisory 981374.
"We recommend that customers install the update as soon as it is available," says Jerry Bryant, group manager: response communications at Microsoft. "Once applied, customers are protected against the known attacks related to Security Advisory 981374.
"We have been monitoring this issue and have determined an out-of-band release is needed to protect customers. For customers using automatic updates, this update will automatically be applied once it is released.
"Additionally, because Security Bulletin MS10-18 is a cumulative update, it will also address nine other vulnerabilities in Internet Explorer that were planned for release on April 13."
The patch will also address a number of other vulnerabilities in versions 6, 7 and 8 of Internet Explorer, although Bryant says none of these have been exploited as yet.