A crafted URL containing specific Unicode characters could have hidden the true origin of the page, resulting in a potential spoofing attack. This vulnerability affects Firefox < 137, Firefox ESR < 128.9, Thunderbird < 137, and Thunderbird < 128.9.
https://www.mozilla.org/security/advisories/mfsa2025-24/
https://www.mozilla.org/security/advisories/mfsa2025-23/
https://www.mozilla.org/security/advisories/mfsa2025-22/