{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-84121","assignerOrgId":"f16b083a-5664-49f3-a51e-8d479e5ed7fe","state":"PUBLISHED","assignerShortName":"mozilla","dateReserved":"2026-09-01T07:25:11.012Z","datePublished":"2026-09-01T12:18:41.535Z","dateUpdated":"2026-09-02T03:55:38.279Z"},"containers":{"cna":{"affected":[{"product":"Firefox","vendor":"Mozilla","versions":[{"status":"unaffected","version":"115.40","lessThanOrEqual":"115.*","versionType":"rpm"},{"status":"unaffected","version":"140.15","lessThanOrEqual":"140.*","versionType":"rpm"},{"status":"unaffected","version":"153.2","lessThanOrEqual":"153.*","versionType":"rpm"},{"status":"unaffected","version":"155","lessThanOrEqual":"*","versionType":"rpm"}]},{"product":"Thunderbird","vendor":"Mozilla","versions":[{"status":"unaffected","version":"140.15","lessThanOrEqual":"140.*","versionType":"rpm"},{"status":"unaffected","version":"153.2","lessThanOrEqual":"153.*","versionType":"rpm"},{"status":"unaffected","version":"155","lessThanOrEqual":"*","versionType":"rpm"}]}],"descriptions":[{"lang":"en","value":"Sandbox escape due to use-after-free in the DOM: Security component. This vulnerability was fixed in Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.","supportingMedia":[{"type":"text/html","base64":false,"value":"Sandbox escape due to use-after-free in the DOM: Security component. This vulnerability was fixed in Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2."}]}],"title":"Sandbox escape due to use-after-free in the DOM: Security component","references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=2059018"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-82/"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-83/"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-84/"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-85/"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-86/"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-87/"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-88/"}],"credits":[{"lang":"en","value":"Yaqoub Aldurayhim"}],"providerMetadata":{"orgId":"f16b083a-5664-49f3-a51e-8d479e5ed7fe","shortName":"mozilla","dateUpdated":"2026-09-01T21:44:08.642Z"}},"adp":[{"problemTypes":[{"descriptions":[{"type":"CWE","cweId":"CWE-416","lang":"en","description":"CWE-416 Use After Free"}]}],"metrics":[{"cvssV3_1":{"scope":"CHANGED","version":"3.1","baseScore":9.6,"attackVector":"NETWORK","baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","integrityImpact":"HIGH","userInteraction":"REQUIRED","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"NONE","confidentialityImpact":"HIGH"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-09-01T00:00:00+00:00","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3","id":"CVE-2026-84121"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-09-02T03:55:38.279Z"}}]}}