An issue present in lowering/register allocation could have led to obscure but deterministic register confusion failures in JITted code that would lead to a potentially exploitable crash. This vulnerability affects Firefox < 91 and Thunderbird < 91.Referenceshttps://www.mozilla.org/security/advisories/mfsa2021-33/https://www.mozilla.org/security/advisories/mfsa2021-36/https://bugzilla.mozilla.org/show_bug.cgi?id=1707774https://security.gentoo.org/glsa/202202-03
