{"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": "2026-03-25T16:25:17.158Z"}, "containers": {"cna": {"affected": [{"product": "Firefox", "vendor": "Mozilla", "versions": [{"lessThan": "149", "status": "affected", "version": "unspecified", "versionType": "custom"}]}, {"product": "Firefox ESR", "vendor": "Mozilla", "versions": [{"lessThan": "140.9", "status": "affected", "version": "unspecified", "versionType": "custom"}]}, {"product": "Thunderbird", "vendor": "Mozilla", "versions": [{"lessThan": "149", "status": "affected", "version": "unspecified", "versionType": "custom"}]}, {"product": "Thunderbird", "vendor": "Mozilla", "versions": [{"lessThan": "140.9", "status": "affected", "version": "unspecified", "versionType": "custom"}]}], "descriptions": [{"lang": "en", "value": "Use-after-free in the Widget: Cocoa component. This vulnerability affects 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 affects 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": "2026-03-24T20:27:43.111Z"}}, "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"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "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": {"id": "CVE-2026-4711", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-03-25T16:25:02.389182Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-416", "description": "CWE-416 Use After Free"}]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-03-25T16:24:53.783Z"}}], "cna": {"title": "Use-after-free in the Widget: Cocoa component", "credits": [{"lang": "en", "value": "Josh Aas"}], "affected": [{"vendor": "Mozilla", "product": "Firefox", "versions": [{"status": "affected", "version": "unspecified", "lessThan": "149", "versionType": "custom"}]}, {"vendor": "Mozilla", "product": "Firefox ESR", "versions": [{"status": "affected", "version": "unspecified", "lessThan": "140.9", "versionType": "custom"}]}, {"vendor": "Mozilla", "product": "Thunderbird", "versions": [{"status": "affected", "version": "unspecified", "lessThan": "149", "versionType": "custom"}]}, {"vendor": "Mozilla", "product": "Thunderbird", "versions": [{"status": "affected", "version": "unspecified", "lessThan": "140.9", "versionType": "custom"}]}], "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/"}], "descriptions": [{"lang": "en", "value": "Use-after-free in the Widget: Cocoa component. This vulnerability affects Firefox < 149, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9.", "supportingMedia": [{"type": "text/html", "value": "Use-after-free in the Widget: Cocoa component. This vulnerability affects Firefox < 149, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9.", "base64": false}]}], "providerMetadata": {"orgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "shortName": "mozilla", "dateUpdated": "2026-03-24T20:27:43.111Z"}}}, "cveMetadata": {"cveId": "CVE-2026-4711", "state": "PUBLISHED", "dateUpdated": "2026-03-25T16:25:17.158Z", "dateReserved": "2026-03-23T23:22:23.818Z", "assignerOrgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "datePublished": "2026-03-24T12:30:36.392Z", "assignerShortName": "mozilla"}, "dataVersion": "5.2"}

{"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 affects 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 &lt; 149, Firefox ESR &lt; 140.9, Thunderbird &lt; 149, y Thunderbird &lt; 140.9."}], "id": "CVE-2026-4711", "lastModified": "2026-03-25T17:17:10.257", "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": "2026-03-26T05:36:59.792881+00:00", "value": {"mitigation_remediation": ["Apply the latest Mozilla security update for Firefox (version 149 or newer, or ESR 140.9 or newer).", "Apply the latest Mozilla security update for Thunderbird (version 149 or newer, or ESR 140.9 or newer)."], "summary": {"action": "Immediate Patch", "impact": "Local code execution"}, "threat_synthesis": {"affected_systems": "Firefox versions earlier than 149 and Firefox ESR earlier than 140.9, as well as Thunderbird versions earlier than 149 and Thunderbird ESR earlier than 140.9, are affected. These releases are no longer supported and do not receive security updates, so the vulnerability remains active for users who stay on these versions.", "description_and_impact": "The flaw is a use\u2011after\u2011free in the Widget: Cocoa component used by Firefox and Thunderbird. It allows a program to read or write memory after the object has been freed, which can corrupt data, crash the application, or enable an attacker to run arbitrary code within the process. The CVE description does not assert that remote exploitation is possible; it suggests a local vulnerability that could be triggered by malicious content such as a web page or an email attachment processed by the component.", "risk_and_exploitability": "With a CVSS score of 9.8 the vulnerability is classified as critical. The EPSS score is below 1%, indicating that widespread exploitation has not been observed. The vulnerability is not listed in CISA\u2019s KEV catalog. The attack vector is inferred to be local, likely involving a malicious web page or email attachment that would cause the compromised Widget: Cocoa component to be loaded and executed within the user\u2019s browser or mail client. Exploitation would require a crafted payload and local execution rather than an active remote attack."}}}}, "created": "2026-03-25T11:47:56.624349+00:00", "updated": "2026-03-26T12:19:58.115405+00:00", "vendors": ["mozilla", "mozilla$PRODUCT$firefox", "mozilla$PRODUCT$firefox_esr"]}