An attacker was able to perform an out-of-bounds read or write on a JavaScript `Promise` object. This vulnerability affects Firefox < 138.0.4, Firefox ESR < 128.10.1, Firefox ESR < 115.23.1, Thunderbird < 128.10.2, and Thunderbird < 138.0.2.
https://www.mozilla.org/security/advisories/mfsa2025-41/
https://www.mozilla.org/security/advisories/mfsa2025-40/
https://www.mozilla.org/security/advisories/mfsa2025-38/
https://www.mozilla.org/security/advisories/mfsa2025-37/
https://www.mozilla.org/security/advisories/mfsa2025-36/
https://lists.debian.org/debian-lts-announce/2025/05/msg00046.html
https://lists.debian.org/debian-lts-announce/2025/05/msg00024.html