{"id":"CVE-2025-0240","title":"Parsing a JavaScript module as JSON could, under some circumstances, cause cross-compartment access, which may result in a use-after-free","summary":"Parsing a JavaScript module as JSON could, under some circumstances, cause cross-compartment access, which may result in a use-after-free. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Thunderbird 134, and Thunderbird 1…","severity":"medium","cvss":4,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","cwe":["CWE-416"],"vendor":"mozilla","product":"firefox","affected":["firefox < 128.6.0","firefox < 134.0","thunderbird < 128.6.0","thunderbird >= 129.0, < 134.0"],"patched":["firefox 134.0","thunderbird 134.0"],"published":"2025-01-07","updated":"2026-09-30","sourceUpdated":"2026-09-30T19:10:01.007","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-0240","references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1929623","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-01/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-02/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-04/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-05/","label":"security@mozilla.org"},{"url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00004.html","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd"],"epss":0.00672,"epssPercentile":0.50188,"ingestedAt":"2026-09-30T19:21:07.218Z","slug":"CVE-2025-0240","body":"## Overview\n\nParsing a JavaScript module as JSON could, under some circumstances, cause cross-compartment access, which may result in a use-after-free. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Thunderbird 134, and Thunderbird 128.6.\n\n## Affected\n\n- `firefox < 128.6.0`\n- `firefox < 134.0`\n- `thunderbird < 128.6.0`\n- `thunderbird >= 129.0, < 134.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `firefox 134.0`\n- `thunderbird 134.0`","depth":"sunlit","depthScore":22,"depthScoreParts":{"impact":22,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}