{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-4711", "assignerOrgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "state": "PUBLISHED", "assignerShortName": "mozilla", "dateReserved": "2026-03-23T23:22:23.818Z", "datePublished": "2026-03-24T12:30:36.392Z", "dateUpdated": "2026-04-13T13:50:48.884Z"}, "containers": {"cna": {"affected": [{"product": "Firefox", "vendor": "Mozilla", "versions": [{"status": "unaffected", "version": "140.9", "lessThanOrEqual": "140.*", "versionType": "rpm"}, {"status": "unaffected", "version": "149", "lessThanOrEqual": "*", "versionType": "rpm"}]}, {"product": "Thunderbird", "vendor": "Mozilla", "versions": [{"status": "unaffected", "version": "140.9", "lessThanOrEqual": "140.*", "versionType": "rpm"}, {"status": "unaffected", "version": "149", "lessThanOrEqual": "*", "versionType": "rpm"}]}], "descriptions": [{"lang": "en", "value": "Use-after-free in the Widget: Cocoa component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "Use-after-free in the Widget: Cocoa component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9."}]}], "title": "Use-after-free in the Widget: Cocoa component", "references": [{"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2017002"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-20/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-22/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-23/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-24/"}], "credits": [{"lang": "en", "value": "Josh Aas"}], "providerMetadata": {"orgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "shortName": "mozilla", "dateUpdated": "2026-04-13T13:50:48.884Z"}}, "adp": [{"problemTypes": [{"descriptions": [{"type": "CWE", "cweId": "CWE-416", "lang": "en", "description": "CWE-416 Use After Free"}]}], "metrics": [{"cvssV3_1": {"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"}}, {"other": {"type": "ssvc", "content": {"timestamp": "2026-03-25T16:25:02.389182Z", "id": "CVE-2026-4711", "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": "2026-03-25T16:25:17.158Z"}}]}}

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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": "Use-after-free in the Widget: Cocoa component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9."}, {"lang": "es", "value": "Uso despu\u00e9s de liberaci\u00f3n en el componente Widget: Cocoa. Esta vulnerabilidad afecta a Firefox < 149, Firefox ESR < 140.9, Thunderbird < 149, y Thunderbird < 140.9."}], "id": "CVE-2026-4711", "lastModified": "2026-04-13T15:17:42.370", "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": "2026-03-24T13:16:07.010", "references": [{"source": "security@mozilla.org", "tags": ["Permissions Required"], "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2017002"}, {"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": "CWE-416"}], "source": "nvd@nist.gov", "type": "Primary"}, {"description": [{"lang": "en", "value": "CWE-416"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}

{"bugzilla": {"description": "firefox: thunderbird: Use-after-free in the Widget: Cocoa component", "id": "2450733", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2450733"}, "csaw": false, "cvss3": {"cvss3_base_score": "6.1", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N", "status": "draft"}, "cwe": "CWE-825", "details": ["A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:\nUse-after-free in the Widget: Cocoa component"], "name": "CVE-2026-4711", "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": "2026-03-24T12:30:36Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-4711\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-4711\nhttps://www.mozilla.org/security/advisories/mfsa2026-22/#CVE-2026-4711\nhttps://www.mozilla.org/security/advisories/mfsa2026-24/#CVE-2026-4711"], "statement": "Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.", "threat_severity": "Moderate"}

{"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": "2026-04-13T15:44:34.933532+00:00", "value": {"mitigation_remediation": ["Upgrade Mozilla Firefox to version 149 or later, or ESR 140.9 or newer, and upgrade Thunderbird to version 149 or later, or ESR 140.9 or newer.", "Verify the update has been installed by checking the browser\u2019s version number and ensuring the Widget Cocoa component is no longer vulnerable."], "summary": {"action": "Immediate Patch", "impact": "Remote Code Execution"}, "threat_synthesis": {"affected_systems": "Mozilla Firefox and Thunderbird versions deployed before the 149 (standard) or ESR 140.9 releases are vulnerable. Any installation remaining on an older build of either browser has the flaw and should be updated.", "description_and_impact": "Use-after-free in the Widget Cocoa component allows memory corruption that can lead to execution of arbitrary code. The flaw arises when the component frees a memory object while a pointer to it is still in use, a pattern captured by CWE-416 and CWE-825. An attacker could exploit the vulnerability to crash the application or execute malicious code in the user\u2019s address space, jeopardizing confidentiality, integrity, or availability of the affected system.", "risk_and_exploitability": "The CVSS base score of 9.8 marks this issue as critical, yet the EPSS is under 1%, indicating a low current exploitation probability, and it is not listed in the CISA KEV catalog. The vector is client\u2011side: a malicious webpage or email that triggers the Widget Cocoa component can invoke the use\u2011after\u2011free, giving the attacker control over the application process. No special conditions are required beyond running the affected software, making exploitation straightforward once the path is known."}}}}, "created": "2026-03-25T11:47:56.624349+00:00", "updated": "2026-04-14T16:42:59.495485+00:00", "vendors": ["mozilla", "mozilla$PRODUCT$firefox", "mozilla$PRODUCT$firefox_esr"]}