On arm64, a WASM `br_table` instruction with a lot of entries could lead to the label being too far from the instruction causing truncation and incorrect computation of the branch address. This vulnerability affects Firefox < 141, Firefox ESR < 115.26, Firefox ESR < 128.13, Firefox ESR < 140.1, Thunderbird < 141, Thunderbird < 128.13, and Thunderbird < 140.1.
https://www.securityweek.com/high-severity-flaws-patched-in-chrome-firefox/
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/mfsa2025-57/