This security update resolves seven privately reported vulnerabilities in Internet Explorer. The most severe vulnerabilities could allow remote code execution if a user views a specially crafted webpage using Internet Explorer. In other words, all you need to do to fall victim is click a link or picture on a friends Facebook feed or enticing holiday offer that directs you to a hacked webpage.
This security update is rated Critical for Internet Explorer 6, Internet Explorer 7, Internet Explorer 8, Internet Explorer 9, Internet Explorer 10, and Internet Explorer 11 on affected Windows clients.
More details can be found here:
http://technet.microsoft.com/en-us/security/bulletin/ms13-097
