Multiple prompts and panels from both Firefox and the Android OS could be used to obscure the notification announcing the transition to fullscreen mode after the fix for CVE-2023-6870 in Firefox 121. This could lead to spoofing the browser UI if the sudden appearance of the prompt distracted the user from noticing the visual transition happening behind the prompt. These notifications now use the Android Toast feature. *This bug only affects Firefox on Android. Other operating systems are unaffected.* This vulnerability affects Firefox < 130.

Memory safety bugs present in Firefox 129, Firefox ESR 128.1, and Thunderbird 128.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 130, Firefox ESR < 128.2, and Thunderbird < 128.2.

If a site had been granted the permission to open popup windows, it could cause Select elements to appear on top of another site to perform a spoofing attack. This vulnerability affects Firefox < 130, Firefox ESR < 128.2, and Thunderbird < 128.2.

A difference in the handling of StructFields and ArrayTypes in WASM could be used to trigger an exploitable type confusion vulnerability. This vulnerability affects Firefox < 130, Firefox ESR < 128.2, and Thunderbird < 128.2.

The JavaScript garbage collector could mis-color cross-compartment objects if OOM conditions were detected at the right point between two passes. This could have led to memory corruption. This vulnerability affects Firefox < 130, Firefox ESR < 128.2, Firefox ESR < 115.15, Thunderbird < 128.2, and Thunderbird < 115.15.

Firefox normally asks for confirmation before asking the operating system to find an application to handle a scheme that the browser does not support. It did not ask before doing so for the Usenet-related schemes news: and snews:. Since most operating systems don't have a trusted newsreader installed by default, an unscrupulous program that the user downloaded could register itself as a handler. The website that served the application download could then launch that application at will. This vulnerability affects Firefox < 130, Firefox ESR < 128.2, and Firefox ESR < 115.15.

Internal browser event interfaces were exposed to web content when privileged EventHandler listener callbacks ran for those events. Web content that tried to use those interfaces would not be able to use them with elevated privileges, but their presence would indicate certain browser features had been used, such as when a user opened the Dev Tools console. This vulnerability affects Firefox < 130, Firefox ESR < 128.2, Firefox ESR < 115.15, Thunderbird < 128.2, and Thunderbird < 115.15.

A potentially exploitable type confusion could be triggered when looking up a property name on an object being used as the `with` environment. This vulnerability affects Firefox < 130, Firefox ESR < 128.2, Firefox ESR < 115.15, Thunderbird < 128.2, and Thunderbird < 115.15.

The contextual menu for links could provide an opportunity for cross-site scripting attacks This vulnerability affects Firefox for iOS < 129.

Long pressing on a download link could potentially provide a means for cross-site scripting This vulnerability affects Firefox for iOS < 129.