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.
https://www.mozilla.org/security/advisories/mfsa2024-43/
https://www.mozilla.org/security/advisories/mfsa2024-40/
https://www.mozilla.org/security/advisories/mfsa2024-39/
https://bugzilla.mozilla.org/show_bug.cgi?id=1909529