{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-74960", "assignerOrgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "state": "PUBLISHED", "assignerShortName": "mozilla", "dateReserved": "2026-08-17T11:58:22.429Z", "datePublished": "2026-08-18T12:23:31.590Z", "dateUpdated": "2026-08-18T18:55:11.473Z"}, "containers": {"cna": {"affected": [{"product": "Firefox", "vendor": "Mozilla", "versions": [{"status": "unaffected", "version": "140.14", "lessThanOrEqual": "140.*", "versionType": "rpm"}, {"status": "unaffected", "version": "153.1", "lessThanOrEqual": "153.*", "versionType": "rpm"}, {"status": "unaffected", "version": "154", "lessThanOrEqual": "*", "versionType": "rpm"}]}, {"product": "Thunderbird", "vendor": "Mozilla", "versions": [{"status": "unaffected", "version": "140.14", "lessThanOrEqual": "140.*", "versionType": "rpm"}, {"status": "unaffected", "version": "153.1", "lessThanOrEqual": "153.*", "versionType": "rpm"}, {"status": "unaffected", "version": "154", "lessThanOrEqual": "*", "versionType": "rpm"}]}], "descriptions": [{"lang": "en", "value": "Site isolation issue in the WebExtensions component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "Site isolation issue in the WebExtensions component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1."}]}], "title": "Site isolation issue in the WebExtensions component", "references": [{"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2049148"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-74/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-76/"}, {"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/mfsa2026-79/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-80/"}], "credits": [{"lang": "en", "value": "Khanh Nguyen"}], "providerMetadata": {"orgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "shortName": "mozilla", "dateUpdated": "2026-08-18T18:55:11.473Z"}}}}

{}

{"affected": [{"affectedData": [{"product": "Firefox", "vendor": "Mozilla", "versions": [{"lessThanOrEqual": "140.*", "status": "unaffected", "version": "140.14", "versionType": "rpm"}, {"lessThanOrEqual": "153.*", "status": "unaffected", "version": "153.1", "versionType": "rpm"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "154", "versionType": "rpm"}]}, {"product": "Thunderbird", "vendor": "Mozilla", "versions": [{"lessThanOrEqual": "140.*", "status": "unaffected", "version": "140.14", "versionType": "rpm"}, {"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": "Site isolation issue in the WebExtensions component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1."}], "id": "CVE-2026-74960", "lastModified": "2026-08-18T19:17:11.543", "metrics": {}, "published": "2026-08-18T13:17:33.170", "references": [{"source": "security@mozilla.org", "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2049148"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-74/"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-76/"}, {"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/mfsa2026-79/"}, {"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": "[140.14,140.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[153.1,153.*]"}}, {"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": "2026-08-18T14:15:07.923066+00:00", "updated": "2026-08-18T14:45:03.537454+00:00", "vendors": ["mozilla", "mozilla$PRODUCT$firefox"], "weaknesses": ["CWE-200", "CWE-264"]}