Insufficient escaping in the “Copy as cURL” feature could potentially be used to trick a user into executing unexpected code. This vulnerability was fixed in Firefox 141, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.
https://www.mozilla.org/security/advisories/mfsa2025-63/
https://www.mozilla.org/security/advisories/mfsa2025-62/
https://www.mozilla.org/security/advisories/mfsa2025-61/
https://www.mozilla.org/security/advisories/mfsa2025-59/
https://www.mozilla.org/security/advisories/mfsa2025-58/
https://www.mozilla.org/security/advisories/mfsa2025-56/
https://lists.debian.org/debian-lts-announce/2025/07/msg00016.html