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.

More... (http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2008-4127)