A malicious website could have included an iframe with an malformed URI resulting in a non-exploitable browser crash. This vulnerability affects Firefox < 126.
Form validation popups could capture escape key presses. Therefore, spamming form validation messages could be used to prevent users from exiting full-screen mode. This vulnerability affects Firefox < 128 and Thunderbird < 128.
Firefox for Android would become unstable and hard-to-recover when a website opened too many popups. *This bug only affects Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 89.
Repeated calls to the history and location interfaces could have been used to hang the browser. This was addressed by introducing rate-limiting to these API calls. This vulnerability affects Firefox < 83.