{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-74938", "assignerOrgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "state": "PUBLISHED", "assignerShortName": "mozilla", "dateReserved": "2026-08-17T11:57:33.871Z", "datePublished": "2026-08-18T12:23:35.938Z", "dateUpdated": "2026-08-18T19:17:35.897Z"}, "containers": {"cna": {"affected": [{"product": "Firefox", "vendor": "Mozilla", "versions": [{"status": "unaffected", "version": "153.1", "lessThanOrEqual": "153.*", "versionType": "rpm"}, {"status": "unaffected", "version": "154", "lessThanOrEqual": "*", "versionType": "rpm"}]}, {"product": "Thunderbird", "vendor": "Mozilla", "versions": [{"status": "unaffected", "version": "153.1", "lessThanOrEqual": "153.*", "versionType": "rpm"}, {"status": "unaffected", "version": "154", "lessThanOrEqual": "*", "versionType": "rpm"}]}], "descriptions": [{"lang": "en", "value": "Mitigation bypass in the JavaScript: GC component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "Mitigation bypass in the JavaScript: GC component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1."}]}], "title": "Mitigation bypass in the JavaScript: GC component", "references": [{"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2053688"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-74/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-77/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-78/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-80/"}], "credits": [{"lang": "en", "value": "Amy Burnett of OpenAI"}], "providerMetadata": {"orgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "shortName": "mozilla", "dateUpdated": "2026-08-18T18:55:28.159Z"}}, "adp": [{"problemTypes": [{"descriptions": [{"type": "CWE", "cweId": "CWE-693", "lang": "en", "description": "CWE-693 Protection Mechanism Failure"}]}], "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.1, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}}, {"other": {"type": "ssvc", "content": {"timestamp": "2026-08-18T19:17:32.598294Z", "id": "CVE-2026-74938", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "total"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-18T19:17:35.897Z"}}]}}

{}

{"affected": [{"affectedData": [{"product": "Firefox", "vendor": "Mozilla", "versions": [{"lessThanOrEqual": "153.*", "status": "unaffected", "version": "153.1", "versionType": "rpm"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "154", "versionType": "rpm"}]}, {"product": "Thunderbird", "vendor": "Mozilla", "versions": [{"lessThanOrEqual": "153.*", "status": "unaffected", "version": "153.1", "versionType": "rpm"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "154", "versionType": "rpm"}]}], "source": "security@mozilla.org"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Mitigation bypass in the JavaScript: GC component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1."}], "id": "CVE-2026-74938", "lastModified": "2026-08-18T19:17:05.583", "metrics": {}, "published": "2026-08-18T13:17:30.103", "references": [{"source": "security@mozilla.org", "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2053688"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-74/"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-77/"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-78/"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-80/"}], "sourceIdentifier": "security@mozilla.org", "vulnStatus": "Undergoing Analysis"}

{}

{"affected": [{"configurations": [{"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[153.1,154.0.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[154,*]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Firefox", "source": "cna", "vendor": "Mozilla"}, "product": "firefox", "vendor": "mozilla"}], "created": "2026-08-18T13:30:13.521083+00:00", "updated": "2026-08-18T14:15:07.922854+00:00", "vendors": ["mozilla", "mozilla$PRODUCT$firefox"]}