CVE-2026-16387

{"id": "CVE-2026-16387", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-16387", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-07-22T17:14:57.789549Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "cvssData": {"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"}, "impactScore": 5.9, "exploitabilityScore": 3.9}]}, "affected": [{"source": "security@mozilla.org", "affectedData": [{"vendor": "Mozilla", "product": "Firefox", "versions": [{"status": "unaffected", "version": "140.13", "versionType": "rpm", "lessThanOrEqual": "140.*"}, {"status": "unaffected", "version": "153", "versionType": "rpm", "lessThanOrEqual": "*"}]}, {"vendor": "Mozilla", "product": "Thunderbird", "versions": [{"status": "unaffected", "version": "140.13", "versionType": "rpm", "lessThanOrEqual": "140.*"}, {"status": "unaffected", "version": "153", "versionType": "rpm", "lessThanOrEqual": "*"}]}]}], "published": "2026-07-21T13:17:13.863", "references": [{"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2043200", "tags": ["Permissions Required"], "source": "security@mozilla.org"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-68/", "tags": ["Vendor Advisory"], "source": "security@mozilla.org"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-70/", "tags": ["Vendor Advisory"], "source": "security@mozilla.org"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-71/", "tags": ["Vendor Advisory"], "source": "security@mozilla.org"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-72/", "tags": ["Vendor Advisory"], "source": "security@mozilla.org"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "description": [{"lang": "en", "value": "CWE-200"}, {"lang": "en", "value": "CWE-284"}, {"lang": "en", "value": "CWE-346"}]}], "descriptions": [{"lang": "en", "value": "Site isolation issue in the Networking component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13."}], "lastModified": "2026-07-24T15:19:03.710", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*", "vulnerable": true, "matchCriteriaId": "0D089F1A-9B89-4584-B58B-046555D9560E", "versionEndExcluding": "140.13.0"}, {"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*", "vulnerable": true, "matchCriteriaId": "5DB4AF59-87C2-4FC4-896D-02879D6F8E6B", "versionEndExcluding": "153.0.0"}, {"criteria": "cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "9F5CEA4A-31D8-46F6-B259-0DFF56BD8F1D", "versionEndExcluding": "140.13.0"}, {"criteria": "cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "B9C46740-CFEC-4FBB-8461-46E26518EE59", "versionEndExcluding": "153.0", "versionStartIncluding": "141.0"}], "operator": "OR"}]}], "sourceIdentifier": "security@mozilla.org"}