Incorrect boundary conditions in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 150, Thunderbird 150, Firefox ESR 140.10.1, Thunderbird 140.10.1, and Firefox ESR 115.35.2.
https://www.mozilla.org/security/advisories/mfsa2026-42/
https://www.mozilla.org/security/advisories/mfsa2026-39/
https://www.mozilla.org/security/advisories/mfsa2026-36/
https://www.mozilla.org/security/advisories/mfsa2026-33/