{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Exim", "vendor": "Exim", "versions": [{"lessThan": "4.99.2", "status": "affected", "version": "0", "versionType": "semver"}]}], "source": "cve@mitre.org"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:exim:exim:*:*:*:*:*:*:*:*", "matchCriteriaId": "E48EAA99-95DA-4695-BBEA-16D09AA0A508", "versionEndExcluding": "4.99.2", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In Exim before 4.99.2, when JSON lookup is enabled, an out-of-bounds heap write can occur when a JSON operator encounters malformed JSON in an untrusted header, because of an incorrect implementation of \\ skipping."}, {"lang": "es", "value": "En Exim anterior a 4.99.2, cuando la b\u00fasqueda JSON est\u00e1 habilitada, puede ocurrir una escritura fuera de l\u00edmites en el heap cuando un operador JSON encuentra JSON malformado en una cabecera no confiable, debido a una implementaci\u00f3n incorrecta del salto de barra invertida."}], "id": "CVE-2026-40685", "lastModified": "2026-11-11T21:10:00.200", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 6.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 4.2, "source": "cve@mitre.org", "type": "Secondary"}, {"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"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-40685", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-05-01T14:26:30.902958Z", "version": "2.0.3"}}]}, "published": "2026-04-30T22:16:25.633", "references": [{"source": "cve@mitre.org", "tags": ["Patch"], "url": "https://code.exim.org/exim/exim/commit/9fdc057e71b87c87a0d3d2288b2810a0efaaba57"}, {"source": "cve@mitre.org", "tags": ["Broken Link"], "url": "https://exim.org/static/doc/security/CVE-2026-40685.txt"}, {"source": "cve@mitre.org", "tags": ["Vendor Advisory"], "url": "https://exim.org/static/doc/security/cve-2026-04.1/CVE2026-40685.assessment"}, {"source": "cve@mitre.org", "tags": ["Mailing List", "Third Party Advisory"], "url": "https://www.openwall.com/lists/oss-security/2026/04/30/21"}], "sourceIdentifier": "cve@mitre.org", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-684"}], "source": "cve@mitre.org", "type": "Secondary"}, {"description": [{"lang": "en", "value": "CWE-787"}], "source": "nvd@nist.gov", "type": "Primary"}]}