Microsoft Internet Explorer 6 SP1 and SP2, 7, and 8 allows remote attackers to execute arbitrary code by accessing an object that (1) was not properly initialized or (2) is deleted, leading to memory corruption, related to the CStyleSheet object and a free of the root container, aka "Memory Corruption Vulnerability."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A7406
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2010/ms10-035
http://www.zerodayinitiative.com/advisories/ZDI-10-102/
http://www.us-cert.gov/cas/techalerts/TA10-159B.html
http://www.securityfocus.com/bid/40417
http://www.securityfocus.com/archive/1/511727/100/0/threaded