Internet Explorer 5 does not modify the security zone for a document that is being loaded into a window until after the document has been loaded, which could allow remote attackers to execute Javascript in a different security context while the document is loading.
Microsoft Internet Explorer 5.01 through 6 allows remote attackers to execute arbitrary code via by instantiating the (1) Mdt2gddr.dll, (2) Mdt2dd.dll, and (3) Mdt2gddo.dll COM objects as ActiveX controls, which leads to memory corruption.
Use-after-free vulnerability in the CRecalcProperty function in mshtml.dll in Microsoft Internet Explorer 5.01 through 7 allows remote attackers to execute arbitrary code by calling the setExpression method and then modifying the outerHTML property of an HTML element, one variant of "Uninitialized Memory Corruption Vulnerability."