{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-4699", "assignerOrgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "state": "PUBLISHED", "assignerShortName": "mozilla", "dateReserved": "2026-03-23T23:22:01.062Z", "datePublished": "2026-03-24T12:30:28.441Z", "dateUpdated": "2026-03-24T20:27:29.108Z"}, "containers": {"cna": {"affected": [{"product": "Firefox", "vendor": "Mozilla", "versions": [{"lessThan": "149", "status": "affected", "version": "unspecified", "versionType": "custom"}]}, {"product": "Firefox ESR", "vendor": "Mozilla", "versions": [{"lessThan": "115.34", "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": "Incorrect boundary conditions in the Layout: Text and Fonts component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "Incorrect boundary conditions in the Layout: Text and Fonts component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9."}]}], "title": "Incorrect boundary conditions in the Layout: Text and Fonts component", "references": [{"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2021863"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-20/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-21/"}, {"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": "Matej Smycka"}], "providerMetadata": {"orgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "shortName": "mozilla", "dateUpdated": "2026-03-24T20:27:29.108Z"}}}}

{}

{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*", "matchCriteriaId": "063BE653-69B0-4543-9A90-BC7A62C943B5", "versionEndExcluding": "115.34.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*", "matchCriteriaId": "02F2B82F-E997-4D5F-BBB0-237E4962555B", "versionEndExcluding": "149.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*", "matchCriteriaId": "525DEC0C-BB47-46C6-9AEB-98F27D4685FE", "versionEndExcluding": "140.9.0", "versionStartIncluding": "128.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Incorrect boundary conditions in the Layout: Text and Fonts component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9."}], "id": "CVE-2026-4699", "lastModified": "2026-03-24T21:16:31.690", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2026-03-24T13:16:05.900", "references": [{"source": "security@mozilla.org", "tags": ["Permissions Required"], "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2021863"}, {"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/mfsa2026-21/"}, {"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-754"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{}

{"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": "[0,115.34)"}}], "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": "[0,140.9)"}}], "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"}], "created": "2026-03-25T11:48:09.957079+00:00", "updated": "2026-03-25T11:48:09.957179+00:00", "vendors": ["mozilla", "mozilla$PRODUCT$firefox", "mozilla$PRODUCT$firefox_esr"]}