Microsoft Internet Explorer before Windows XP Service Pack 2 and Windows Server 2003 Service Pack 1, when Prompt is configured in Security Settings, uses modal dialogs to verify that a user wishes to run an ActiveX control or perform other risky actions, which allows user-assisted remote attackers to construct a race condition that tricks a user into clicking an object or pressing keys that are actually applied to a "Yes" approval for executing the control.

Microsoft Internet Explorer 6 and 7 Beta 2 allows remote attackers to cause a denial of service and possibly execute arbitrary code via a certain createTextRange call on a checkbox object, which results in a dereference of an invalid table pointer.

urlmon.dll in Microsoft Internet Explorer 7.0 beta 2 (aka 7.0.5296.0) allows remote attackers to cause a denial of service (application crash) and possibly execute arbitrary code via a BGSOUND element with its SRC attribute set to "file://" followed by a large number of "-" (dash of hyphen) characters.

Internet Explorer 5.01 through 6 allows remote attackers to spoof arbitrary web sites by injecting content from one window into another window whose name is known but resides in a different domain, as demonstrated using a pop-up window on a trusted web site, aka the "window injection" vulnerability. NOTE: later research shows that Internet Explorer 7 on Windows XP SP2 is also vulnerable.