Firefox and Thunderbird are vulnerable to Fullscreen Notification Obscuring. The vulnerability is due to a website being able to obscure the fullscreen notification by using a dropdown select input element. This could lead to user confusion and possible spoofing attacks in Firefox and Thunderbird.
bugzilla.mozilla.org/show_bug.cgi?id=1832627
lists.debian.org/debian-lts-announce/2024/03/msg00000.html
lists.debian.org/debian-lts-announce/2024/03/msg00001.html
security-tracker.debian.org/tracker/CVE-2024-1548
www.mozilla.org/security/advisories/mfsa2024-05/
www.mozilla.org/security/advisories/mfsa2024-06/
www.mozilla.org/security/advisories/mfsa2024-07/