{"id":"CVE-2026-4702","state":"PUBLISHED","title":"JIT miscompilation in the JavaScript Engine component","description":"JIT miscompilation in the JavaScript Engine component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.","publishedAt":"2026-03-24T12:30:30.743Z","updatedAt":"2026-04-13T13:50:24.307Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"CISA-ADP"},"assigner":"mozilla","products":["Mozilla Firefox","Mozilla Thunderbird"],"affected":[{"vendor":"Mozilla","product":"Firefox","versions":[{"version":"140.9","status":"unaffected","lessThanOrEqual":"140.*","versionType":"rpm"},{"version":"149","status":"unaffected","lessThanOrEqual":"*","versionType":"rpm"}]},{"vendor":"Mozilla","product":"Thunderbird","versions":[{"version":"140.9","status":"unaffected","lessThanOrEqual":"140.*","versionType":"rpm"},{"version":"149","status":"unaffected","lessThanOrEqual":"*","versionType":"rpm"}]}],"references":["https://bugzilla.mozilla.org/show_bug.cgi?id=2013560","https://www.mozilla.org/security/advisories/mfsa2026-20/","https://www.mozilla.org/security/advisories/mfsa2026-22/","https://www.mozilla.org/security/advisories/mfsa2026-23/","https://www.mozilla.org/security/advisories/mfsa2026-24/"],"weaknesses":["CWE-843"],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/4xxx/CVE-2026-4702.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-4702","state":"PUBLISHED","datePublished":"2026-03-24T12:30:30.743Z","dateUpdated":"2026-04-13T13:50:24.307Z","assignerShortName":"mozilla","assignerOrgId":"f16b083a-5664-49f3-a51e-8d479e5ed7fe","dateReserved":"2026-03-23T23:22:07.529Z"},"containers":{"cna":{"title":"JIT miscompilation in the JavaScript Engine component","descriptions":[{"lang":"en","value":"JIT miscompilation in the JavaScript Engine component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9."}],"affected":[{"vendor":"Mozilla","product":"Firefox","versions":[{"version":"140.9","status":"unaffected","lessThanOrEqual":"140.*","versionType":"rpm"},{"version":"149","status":"unaffected","lessThanOrEqual":"*","versionType":"rpm"}]},{"vendor":"Mozilla","product":"Thunderbird","versions":[{"version":"140.9","status":"unaffected","lessThanOrEqual":"140.*","versionType":"rpm"},{"version":"149","status":"unaffected","lessThanOrEqual":"*","versionType":"rpm"}]}],"references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=2013560"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-20/"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-22/"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-23/"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-24/"}],"providerMetadata":{"shortName":"mozilla","orgId":"f16b083a-5664-49f3-a51e-8d479e5ed7fe","dateUpdated":"2026-04-13T13:50:24.307Z"},"credits":[{"lang":"en","value":"Evyatar Ben Asher, Keane Lucas, Nicholas Carlini, Newton Cheng, Daniel Freeman, Alex Gaynor, and Joel Weinberger using Claude from Anthropic"}]},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":9.8,"attackVector":"NETWORK","baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","integrityImpact":"HIGH","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"NONE","confidentialityImpact":"HIGH"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-03-25T19:48:14.570163Z","id":"CVE-2026-4702","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-843","type":"CWE","lang":"en","description":"CWE-843 Access of Resource Using Incompatible Type ('Type Confusion')"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-03-25T19:50:15.573Z"}}]}}}