{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-2764", "assignerOrgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "state": "PUBLISHED", "assignerShortName": "mozilla", "dateReserved": "2026-02-19T15:05:32.669Z", "datePublished": "2026-02-24T13:33:03.207Z", "dateUpdated": "2026-04-16T14:27:18.103Z"}, "containers": {"cna": {"affected": [{"product": "Firefox", "vendor": "Mozilla", "versions": [{"status": "unaffected", "version": "115.33", "lessThanOrEqual": "115.*", "versionType": "rpm"}, {"status": "unaffected", "version": "140.8", "lessThanOrEqual": "140.*", "versionType": "rpm"}, {"status": "unaffected", "version": "148", "lessThanOrEqual": "*", "versionType": "rpm"}]}, {"product": "Thunderbird", "vendor": "Mozilla", "versions": [{"status": "unaffected", "version": "140.8", "lessThanOrEqual": "140.*", "versionType": "rpm"}, {"status": "unaffected", "version": "148", "lessThanOrEqual": "*", "versionType": "rpm"}]}], "descriptions": [{"lang": "en", "value": "JIT miscompilation, use-after-free in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "JIT miscompilation, use-after-free in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8."}]}], "title": "JIT miscompilation, use-after-free in the JavaScript Engine: JIT component", "references": [{"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2012608"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-13/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-14/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-15/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-16/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-17/"}], "credits": [{"lang": "en", "value": "Evyatar Ben Asher, Keane Lucas, Nicholas Carlini, Newton Cheng, Daniel Freeman, Alex Gaynor, and Joel Weinberger using Claude from Anthropic"}], "providerMetadata": {"orgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "shortName": "mozilla", "dateUpdated": "2026-04-13T13:52:30.063Z"}}, "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": "2026-02-28T02:27:58.171528Z", "id": "CVE-2026-2764", "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": "2026-04-16T14:27:18.103Z"}}]}}

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{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*", "matchCriteriaId": "1B590E0E-4C6F-4F2A-A0FF-9BEDA1A36D17", "versionEndExcluding": "115.33.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*", "matchCriteriaId": "3D8676DB-4A12-41A0-A1A5-2DED97287973", "versionEndExcluding": "148.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*", "matchCriteriaId": "AE16902C-47B5-438D-A4A5-770C08223931", "versionEndExcluding": "140.8.0", "versionStartIncluding": "128.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*", "matchCriteriaId": "73228A3D-A71B-497B-A5BA-412FFE9F6F37", "versionEndExcluding": "140.8.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*", "matchCriteriaId": "C5EBE90D-1996-4578-B715-605B24E66C59", "versionEndExcluding": "148.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "JIT miscompilation, use-after-free in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8."}, {"lang": "es", "value": "Error de compilaci\u00f3n JIT, uso despu\u00e9s de liberaci\u00f3n en el motor JavaScript: componente JIT. Esta vulnerabilidad afecta a Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, y Thunderbird < 140.8."}], "id": "CVE-2026-2764", "lastModified": "2026-04-13T15:17:21.690", "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": "2026-02-24T14:16:24.737", "references": [{"source": "security@mozilla.org", "tags": ["Issue Tracking", "Permissions Required"], "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2012608"}, {"source": "security@mozilla.org", "tags": ["Vendor Advisory"], "url": "https://www.mozilla.org/security/advisories/mfsa2026-13/"}, {"source": "security@mozilla.org", "tags": ["Vendor Advisory"], "url": "https://www.mozilla.org/security/advisories/mfsa2026-14/"}, {"source": "security@mozilla.org", "tags": ["Vendor Advisory"], "url": "https://www.mozilla.org/security/advisories/mfsa2026-15/"}, {"source": "security@mozilla.org", "tags": ["Vendor Advisory"], "url": "https://www.mozilla.org/security/advisories/mfsa2026-16/"}, {"source": "security@mozilla.org", "tags": ["Vendor Advisory"], "url": "https://www.mozilla.org/security/advisories/mfsa2026-17/"}], "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: JIT miscompilation, use-after-free in the JavaScript Engine: JIT component", "id": "2442329", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2442329"}, "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"}, "details": ["No description is available for this CVE."], "name": "CVE-2026-2764", "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:6", "fix_state": "Out of support scope", "package_name": "firefox", "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:8", "fix_state": "Affected", "package_name": "firefox", "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"}], "public_date": "2026-02-24T13:33:03Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-2764\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-2764\nhttps://www.mozilla.org/security/advisories/mfsa2026-15/#CVE-2026-2764"], "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": "[0,148)"}}], "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": "[0,115.33)"}}], "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"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,140.8)"}}], "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"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,148)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Thunderbird", "source": "cna", "vendor": "Mozilla"}, "product": "thunderbird", "vendor": "mozilla"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,140.8)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Thunderbird", "source": "cna", "vendor": "Mozilla"}, "product": "thunderbird", "vendor": "mozilla"}], "analysis": {"en": {"generated_at": "2026-04-15T16:12:39.175479+00:00", "value": {"mitigation_remediation": ["Upgrade all affected installations to Firefox\u202f148 or newer, Firefox\u202fESR\u202f115.33 or\u202f140.8, and Thunderbird\u202f148 or\u202f140.8.", "If patching cannot be performed immediately, set the preference javascript.options.baselinejit to false to disable the JIT compiler for JavaScript, reducing the chance of exploitation.", "Implement an organization\u2011wide automatic update policy for Firefox and Thunderbird and restrict JavaScript execution from untrusted origins until the patch is available."], "summary": {"action": "Immediate Patch", "impact": "Remote Code Execution"}, "threat_synthesis": {"affected_systems": "Mozilla Firefox versions prior to 148, Firefox ESR 115.33 and 140.8, and Mozilla Thunderbird versions prior to 148 and 140.8 are affected.", "description_and_impact": "A miscompilation in Firefox and Thunderbird\u2019s JavaScript engine JIT component creates a use\u2011after\u2011free condition (CWE\u2011416). When an attacker can cause the miscompiled code to run, the freed memory can be accessed or overwritten, allowing arbitrary machine instructions to be executed inside the affected process. This can lead to full takeover of the browser or mail client, leaking or tampering with data and potentially disrupting system availability.", "risk_and_exploitability": "The vulnerability carries a CVSS score of 9.8, indicating high severity. The EPSS score is below 1\u202f%, suggesting a low current probability of exploitation, but the potential impact remains serious. It has not been listed in CISA\u2019s KEV catalog. Exploitation would most likely occur through malicious JavaScript executed in a web page or other scriptable context, providing remote attackers with a path to memory corruption and code execution if the conditions for the miscompilation are met."}}}}, "created": "2026-02-25T11:39:42.948294+00:00", "updated": "2026-04-15T17:15:10.585964+00:00", "vendors": ["mozilla", "mozilla$PRODUCT$firefox", "mozilla$PRODUCT$firefox_esr", "mozilla$PRODUCT$thunderbird"]}