The toStaticHTML API (aka the SafeHTML component) in Microsoft Internet Explorer 8 and 9, Communicator 2007 R2, and Lync 2010 and 2010 Attendee does not properly handle event attributes and script, which makes it easier for remote attackers to conduct cross-site scripting (XSS) attacks via a crafted HTML document, aka "HTML Sanitization Vulnerability."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A15530
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2012/ms12-050
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2012/ms12-039
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2012/ms12-037