CVE-2026-34479

{"id": "CVE-2026-34479", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-34479", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-04-10T17:45:24.466114Z"}}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 3.9}], "cvssMetricV40": [{"type": "Secondary", "source": "security@apache.org", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 6.9, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "LOW", "vulnIntegrityImpact": "NONE", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "security@apache.org", "affectedData": [{"cpes": ["cpe:2.3:a:apache:log4j_1_2_api:*:*:*:*:*:*:*:*"], "vendor": "Apache Software Foundation", "product": "Apache Log4j 1 to Log4j 2 bridge", "versions": [{"status": "affected", "version": "2.7", "lessThan": "2.25.4", "versionType": "maven"}, {"status": "affected", "version": "3.0.0-alpha1", "versionType": "maven", "lessThanOrEqual": "3.0.0-beta2"}], "packageURL": "pkg:maven/org.apache.logging.log4j/log4j-1.2-api", "packageName": "org.apache.logging.log4j:log4j-1.2-api", "collectionURL": "https://repo.maven.apache.org/maven2", "defaultStatus": "unaffected"}]}], "published": "2026-04-10T16:16:31.270", "references": [{"url": "https://github.com/apache/logging-log4j2/pull/4078", "tags": ["Exploit", "Issue Tracking", "Patch"], "source": "security@apache.org"}, {"url": "https://lists.apache.org/thread/gd0hp6mj17rn3kj279vgy4p7kd4zz5on", "tags": ["Mailing List"], "source": "security@apache.org"}, {"url": "https://logging.apache.org/cyclonedx/vdr.xml", "tags": ["Vendor Advisory"], "source": "security@apache.org"}, {"url": "https://logging.apache.org/log4j/2.x/migrate-from-log4j1.html", "tags": ["Mitigation"], "source": "security@apache.org"}, {"url": "https://logging.apache.org/security.html#CVE-2026-34479", "tags": ["Vendor Advisory"], "source": "security@apache.org"}, {"url": "http://www.openwall.com/lists/oss-security/2026/04/10/8", "tags": ["Mailing List"], "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security@apache.org", "description": [{"lang": "en", "value": "CWE-116"}]}], "descriptions": [{"lang": "en", "value": "The Log4j1XmlLayout from the Apache Log4j 1-to-Log4j 2 bridge fails to escape characters forbidden by the XML 1.0 standard, producing malformed XML output. Conforming XML parsers are required to reject documents containing such characters with a fatal error, which may cause downstream log processing systems to drop or fail to index affected records.\n\nTwo groups of users are affected:\n\n * Those using Log4j1XmlLayout directly in a Log4j Core 2 configuration file.\n * Those using the Log4j 1 configuration compatibility layer with org.apache.log4j.xml.XMLLayout specified as the layout class.\n\n\nUsers are advised to upgrade to Apache Log4j 1-to-Log4j 2 bridge version 2.25.4, which corrects this issue.\n\nNote: The Apache Log4j 1-to-Log4j 2 bridge is deprecated and will not be present in Log4j 3. Users are encouraged to consult the Log4j 1 to Log4j 2 migration guide https://logging.apache.org/log4j/2.x/migrate-from-log4j1.html , and specifically the section on eliminating reliance on the bridge."}, {"lang": "es", "value": "El Log4j1XmlLayout del puente Apache Log4j 1-a-Log4j 2 no logra escapar caracteres prohibidos por el est\u00e1ndar XML 1.0, produciendo una salida XML mal formada. Los analizadores XML conformes deben rechazar documentos que contengan dichos caracteres con un error fatal, lo que puede causar que los sistemas de procesamiento de registros posteriores descarten o no logren indexar los registros afectados.\n\nDos grupos de usuarios se ven afectados:\n\n * Aquellos que utilizan Log4j1XmlLayout directamente en un archivo de configuraci\u00f3n de Log4j Core 2.\n * Aquellos que utilizan la capa de compatibilidad de configuraci\u00f3n de Log4j 1 con org.apache.log4j.xml.XMLLayout especificado como la clase de dise\u00f1o.\n\nSe aconseja a los usuarios actualizar al puente Apache Log4j 1-a-Log4j 2 versi\u00f3n 2.25.4, que corrige este problema.\n\nNota: El puente Apache Log4j 1-a-Log4j 2 est\u00e1 obsoleto y no estar\u00e1 presente en Log4j 3. Se anima a los usuarios a consultar la gu\u00eda de migraci\u00f3n de Log4j 1 a Log4j 2 https://logging.apache.org/log4j/2.x/migrate-from-log4j1.html, y espec\u00edficamente la secci\u00f3n sobre la eliminaci\u00f3n de la dependencia del puente."}], "lastModified": "2026-10-26T21:10:00.170", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:apache:log4j:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "4D7C1729-01D6-4981-B3FB-3A877083AE28", "versionEndExcluding": "2.25.4", "versionStartIncluding": "2.7"}, {"criteria": "cpe:2.3:a:apache:log4j:3.0.0:alpha1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "5EE518C3-2F43-40FF-B754-C340B7003FC7"}, {"criteria": "cpe:2.3:a:apache:log4j:3.0.0:alpha1_rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "6D2A01C1-D56C-4198-8ADB-11739F791E2B"}, {"criteria": "cpe:2.3:a:apache:log4j:3.0.0:alpha1_rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D6F8BD61-DD30-4D64-842C-850E5B117036"}, {"criteria": "cpe:2.3:a:apache:log4j:3.0.0:beta1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "ED00C38D-27EA-489C-9A2B-3594ACA8A3C5"}, {"criteria": "cpe:2.3:a:apache:log4j:3.0.0:beta2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "8794D719-1D90-4378-B48B-698EA40FBFB2"}], "operator": "OR"}]}], "sourceIdentifier": "security@apache.org"}