Microsoft Internet Explorer 5.01 through 6 allows remote attackers to execute arbitrary code via HTML elements with a certain crafted tag, which leads to memory corruption.

Internet Explorer 6.0, and possibly other versions, allows remote attackers to bypass the same origin security policy and make requests outside of the intended domain by calling open on an XMLHttpRequest object (Microsoft.XMLHTTP) and using tab, newline, and carriage return characters within the first argument (method name), which is supported by some proxy servers that convert tabs to spaces. NOTE: this issue can be leveraged to conduct referer spoofing, HTTP Request Smuggling, and other attacks.

Microsoft Internet Explorer 6 SP2 6.0.2900.2180 and 6.0.2800.1106, and earlier versions, allows remote attackers to cause a denial of service (crash) and execute arbitrary code via a Javascript BODY onload event that calls the window function, aka "Mismatched Document Object Model Objects Memory Corruption Vulnerability."

Microsoft Internet Explorer 6.0.2800.1106 on Microsoft Windows XP SP2, and other versions including 5.01 and 5.5, allows remote web servers to bypass zone restrictions and execute arbitrary code in the local computer zone by redirecting a function to another function with the same name, as demonstrated by SimilarMethodNameRedir, aka the "Similar Method Name Redirection Cross Domain Vulnerability."

The Windows Shell application in Windows 98, Windows ME, Windows NT 4.0, Windows 2000, Windows XP, and Windows Server 2003 allows remote attackers to execute arbitrary code by spoofing the type of a file via a CLSID specifier in the filename, as demonstrated using Internet Explorer 6.0.2800.1106 on Windows XP.

Internet Explorer 6.0 does not warn users when an expired certificate authority (CA) certificate is submitted to the user and a newer CA certificate is in the user's local repository, which could allow remote attackers to decrypt web sessions via a man-in-the-middle (MITM) attack.