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{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*", "matchCriteriaId": "DA62D95E-CB01-4586-83DB-5094116FC939", "versionEndExcluding": "140.9.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*", "matchCriteriaId": "02F2B82F-E997-4D5F-BBB0-237E4962555B", "versionEndExcluding": "149.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Mitigation bypass in the Networking: HTTP component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9."}, {"lang": "es", "value": "Elusi\u00f3n de mitigaci\u00f3n en el componente de Redes: HTTP. Esta vulnerabilidad afecta a Firefox < 149, Firefox ESR < 140.9, Thunderbird < 149, y Thunderbird < 140.9."}], "id": "CVE-2026-4700", "lastModified": "2026-04-13T15:17:39.530", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.9, "source": "nvd@nist.gov", "type": "Primary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.9, "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}, "published": "2026-03-24T13:16:06.003", "references": [{"source": "security@mozilla.org", "tags": ["Permissions Required"], "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2003766"}, {"source": "security@mozilla.org", "tags": ["Vendor Advisory"], "url": "https://www.mozilla.org/security/advisories/mfsa2026-20/"}, {"source": "security@mozilla.org", "tags": ["Vendor Advisory"], "url": "https://www.mozilla.org/security/advisories/mfsa2026-22/"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-23/"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-24/"}], "sourceIdentifier": "security@mozilla.org", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "NVD-CWE-noinfo"}], "source": "nvd@nist.gov", "type": "Primary"}, {"description": [{"lang": "en", "value": "CWE-288"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}

{"bugzilla": {"description": "firefox: thunderbird: Mitigation bypass in the Networking: HTTP component", "id": "2450752", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2450752"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-444", "details": ["A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:\nMitigation bypass in the Networking: HTTP component"], "name": "CVE-2026-4700", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "rhel10/firefox-flatpak", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "rhel10/thunderbird-flatpak", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "thunderbird", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "thunderbird", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Out of support scope", "package_name": "thunderbird", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "thunderbird", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "thunderbird", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-03-24T12:30:28Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-4700\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-4700\nhttps://www.mozilla.org/security/advisories/mfsa2026-22/#CVE-2026-4700\nhttps://www.mozilla.org/security/advisories/mfsa2026-24/#CVE-2026-4700"], "statement": "Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.", "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,149)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Firefox", "source": "cna", "vendor": "Mozilla"}, "product": "firefox", "vendor": "mozilla"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,140.9)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Firefox ESR", "source": "cna", "vendor": "Mozilla"}, "product": "firefox_esr", "vendor": "mozilla"}], "analysis": {"en": {"generated_at": "2026-04-13T16:19:57.220167+00:00", "value": {"mitigation_remediation": ["Upgrade Firefox to version\u202f149 or later, or to Firefox ESR\u202f140.9 or later. ", "Upgrade Thunderbird to version\u202f149 or later, or to Thunderbird ESR\u202f140.9 or later."], "summary": {"action": "Patch", "impact": "Bypass of HTTP mitigation controls"}, "threat_synthesis": {"affected_systems": "Affected are Firefox versions prior to\u202f149 and prior to ESR\u202f140.9, as well as Thunderbird versions prior to\u202f149 and prior to ESR\u202f140.9. The issue is specific to the HTTP networking subsystem shared by these applications.", "description_and_impact": "The vulnerability is a mitigation bypass in the Networking\u00a0:\u00a0HTTP component of Mozilla products. The flaw allows an attacker to evade built\u2011in HTTP security protections. By injecting specially crafted HTTP traffic, the attacker can undermine the intended security controls. This weakness is described with CWE\u2011288 and CWE\u2011444.", "risk_and_exploitability": "The CVSS score of\u202f9.8 indicates critical severity. The EPSS score falls below\u202f1\u202f%, so exploitation is unlikely at present. The flaw is not listed in the CISA KEV catalog, suggesting no documented widespread attacks. Likely the attack vector is remote over the network, with an attacker able to craft HTTP requests to a vulnerable client."}}}}, "created": "2026-03-25T11:48:08.946885+00:00", "updated": "2026-04-14T16:43:29.270586+00:00", "vendors": ["mozilla", "mozilla$PRODUCT$firefox", "mozilla$PRODUCT$firefox_esr"]}