Microsoft Internet Explorer 8 and earlier, and Internet Explorer 9 beta, does not properly restrict cross-zone drag-and-drop actions, which allows user-assisted remote attackers to read cookie files via vectors involving an IFRAME element with a SRC attribute containing a file: URL, as demonstrated by a Facebook game, related to a "cookiejacking" issue.
Microsoft Internet Explorer 6 through 9, and 10 Consumer Preview, allows remote attackers to bypass Protected Mode or cause a denial of service (memory corruption) by leveraging access to a Low integrity process, as demonstrated by VUPEN during a Pwn2Own competition at CanSecWest 2012.
Mshtml.dll in Microsoft Internet Explorer 7 Gold 7.0.5730 and 8 Beta 8.0.6001 on Windows XP SP2 allows remote attackers to cause a denial of service (failure of subsequent image rendering) via a crafted PNG file, related to an infinite loop in the CDwnTaskExec::ThreadExec function.
Stack-based buffer overflow in the AddFavorite method in Microsoft Internet Explorer allows remote attackers to cause a denial of service (application crash) and possibly have unspecified other impact via a long URL in the first argument.