Mozilla before 1.4.2 executes Javascript events in the context of a new page while it is being loaded, allowing it to interact with the previous page (zombie document) and enable cross-domain and cross-site scripting (XSS) attacks, as demonstrated using onmousemove events.

The POP3 mail client in Mozilla 1.0 and earlier, and Netscape Communicator 4.7 and earlier, allows remote attackers to cause a denial of service (no new mail) via a mail message containing a dot (.) at a newline, which is interpreted as the end of the message.

Mozilla 0.9.6 and earlier and Netscape 6.2 and earlier allows remote attackers to steal cookies from another domain via a link with a hex-encoded null character (%00) followed by the target domain.

Mozilla 1.1 and earlier, and Mozilla-based browsers such as Netscape and Galeon, set the document referrer too quickly in certain situations when a new page is being loaded, which allows web pages to determine the next page that is being visited, including manually entered URLs, using the onunload handler.