mshtml.dll 6.00.2900.2873, as used in Microsoft Internet Explorer, allows remote attackers to cause a denial of service (crash) via nested OBJECT tags, which trigger invalid pointer dereferences including NULL dereferences. NOTE: the possibility of code execution was originally theorized, but Microsoft has stated that this issue is non-exploitable.

Interpretation conflict between Internet Explorer and other web browsers such as Mozilla, Opera, and Firefox might allow remote attackers to modify the visual presentation of web pages and possibly bypass protection mechanisms such as content filters via ASCII characters with the 8th bit set, which could be stripped by Internet Explorer to render legible text, but not when using other browsers. NOTE: there has been significant discussion about this issue, and as of 20060625, it is not clear where the responsibility for this issue lies, although it might be due to vagueness within the associated standards. NOTE: this might only be exploitable with certain encodings.

mshtml.dll in Microsoft Internet Explorer 6.0.2800 allows remote attackers to cause a denial of service (crash) via a table containing a form that crosses multiple td elements, and whose "float: left" class is defined in a link to a CSS stylesheet after the end of the table, which may trigger a null dereference.