A background script invoking <code>requestFullscreen</code> and then blocking the main thread could force the browser into fullscreen mode indefinitely, resulting in potential user confusion or spoofing attacks. This vulnerability affects Firefox < 110, Thunderbird < 102.8, and Firefox ESR < 102.8.
https://www.mozilla.org/security/advisories/mfsa2023-07/
https://www.mozilla.org/security/advisories/mfsa2023-06/