Parsing a JavaScript module as JSON could, under some circumstances, cause cross-compartment access, which may result in a use-after-free. This vulnerability affects Firefox < 134, Firefox ESR < 128.6, Thunderbird < 134, and Thunderbird < 128.6.CreditsNils BarsReferenceshttps://bugzilla.mozilla.org/show_bug.cgi?id=1929623https://www.mozilla.org/security/advisories/mfsa2025-01/https://www.mozilla.org/security/advisories/mfsa2025-02/https://www.mozilla.org/security/advisories/mfsa2025-04/https://www.mozilla.org/security/advisories/mfsa2025-05/