An attacker could cause a select dropdown to be shown over another tab; this could have led to user confusion and possible spoofing attacks. This vulnerability affects Firefox < 133, Firefox ESR < 128.5, Thunderbird < 133, and Thunderbird < 128.5.
https://www.mozilla.org/security/advisories/mfsa2024-68/
https://www.mozilla.org/security/advisories/mfsa2024-67/
https://www.mozilla.org/security/advisories/mfsa2024-64/