The broker EditWith feature in Microsoft Internet Explorer 8 through 11 allows remote attackers to bypass the AppContainer protection mechanism and gain privileges via a DelegateExecute launch of an arbitrary application, as demonstrated by a transition from Low Integrity to Medium Integrity, aka "Internet Explorer Elevation of Privilege Vulnerability."
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2015/ms15-106