By confusing the browser, the fullscreen notification could have been delayed or suppressed, resulting in potential user confusion or spoofing attacks. This vulnerability affects Firefox < 108.
https://www.mozilla.org/security/advisories/mfsa2022-51/
https://www.debian.org/security/2023/dsa-5355
https://www.debian.org/security/2023/dsa-5322
https://security.gentoo.org/glsa/202305-13
https://security.gentoo.org/glsa/202305-06
https://lists.debian.org/debian-lts-announce/2023/02/msg00018.html
https://lists.debian.org/debian-lts-announce/2023/01/msg00015.html