CVE-2026-34477

{"id": "CVE-2026-34477", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-34477", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-04-10T17:36:46.652477Z"}}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.9, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 2.2}], "cvssMetricV40": [{"type": "Secondary", "source": "security@apache.org", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 6.3, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/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": "HIGH", "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": "LOW", "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:*:*:*:*:*:*:*:*"], "vendor": "Apache Software Foundation", "product": "Apache Log4j Core", "versions": [{"status": "affected", "version": "2.12.0", "lessThan": "2.25.4", "versionType": "maven"}, {"status": "affected", "version": "3.0.0-alpha1", "versionType": "maven", "lessThanOrEqual": "3.0.0-beta3"}], "packageURL": "pkg:maven/org.apache.logging.log4j/log4j-core", "packageName": "org.apache.logging.log4j:log4j-core", "collectionURL": "https://repo.maven.apache.org/maven2", "defaultStatus": "unaffected"}]}], "published": "2026-04-10T16:16:30.843", "references": [{"url": "https://github.com/apache/logging-log4j2/pull/4075", "tags": ["Issue Tracking", "Patch"], "source": "security@apache.org"}, {"url": "https://lists.apache.org/thread/lkx8cl46t2bvkcwfcb2pd43ygc097lq4", "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/manual/appenders/network.html#SslConfiguration-attr-verifyHostName", "tags": ["Product"], "source": "security@apache.org"}, {"url": "https://logging.apache.org/security.html#CVE-2026-34477", "tags": ["Vendor Advisory"], "source": "security@apache.org"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security@apache.org", "description": [{"lang": "en", "value": "CWE-297"}]}, {"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-295"}]}], "descriptions": [{"lang": "en", "value": "The fix for CVE-2025-68161 https://logging.apache.org/security.html#CVE-2025-68161 was incomplete: it addressed hostname verification only when enabled via the log4j2.sslVerifyHostName https://logging.apache.org/log4j/2.x/manual/systemproperties.html#log4j2.sslVerifyHostName system property, but not when configured through the verifyHostName https://logging.apache.org/log4j/2.x/manual/appenders/network.html#SslConfiguration-attr-verifyHostName attribute of the <Ssl> element.\n\nAlthough the verifyHostName configuration attribute was introduced in Log4j Core 2.12.0, it was silently ignored in all versions through 2.25.3, leaving TLS connections vulnerable to interception regardless of the configured value.\n\nA network-based attacker may be able to perform a man-in-the-middle attack when all of the following conditions are met:\n\n * An SMTP, Socket, or Syslog appender is in use.\n * TLS is configured via a nested <Ssl> element.\n * The attacker can present a certificate issued by a CA trusted by the appender's configured trust store, or by the default Java trust store if none is configured.\nThis issue does not affect users of the HTTP appender, which uses a separate verifyHostname https://logging.apache.org/log4j/2.x/manual/appenders/network.html#HttpAppender-attr-verifyHostName attribute that was not subject to this bug and verifies host names by default.\n\nUsers are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue."}, {"lang": "es", "value": "La correcci\u00f3n para CVE-2025-68161 https://logging.apache.org/security.html#CVE-2025-68161 fue incompleta: abordaba la verificaci\u00f3n del nombre de host solo cuando se habilitaba a trav\u00e9s de la propiedad del sistema log4j2.sslVerifyHostName https://logging.apache.org/log4j/2.x/manual/systemproperties.html#log4j2.sslVerifyHostName, pero no cuando se configuraba a trav\u00e9s del atributo verifyHostName https://logging.apache.org/log4j/2.x/manual/appenders/network.html#SslConfiguration-attr-verifyHostName del elemento [Ssl].\n\nAunque el atributo de configuraci\u00f3n verifyHostName se introdujo en Log4j Core 2.12.0, fue ignorado silenciosamente en todas las versiones hasta la 2.25.3, dejando las conexiones TLS vulnerables a la intercepci\u00f3n independientemente del valor configurado.\n\nUn atacante basado en red podr\u00eda realizar un ataque man-in-the-middle cuando se cumplen todas las siguientes condiciones:\n\n * Se est\u00e1 utilizando un appender SMTP, Socket o Syslog.\n * TLS est\u00e1 configurado a trav\u00e9s de un elemento [Ssl] anidado.\n * El atacante puede presentar un certificado emitido por una CA de confianza para el almac\u00e9n de confianza configurado del appender, o por el almac\u00e9n de confianza predeterminado de Java si no hay ninguno configurado.\nEste problema no afecta a los usuarios del appender HTTP, que utiliza un atributo verifyHostname https://logging.apache.org/log4j/2.x/manual/appenders/network.html#HttpAppender-attr-verifyHostName separado que no estaba sujeto a este error y verifica los nombres de host por defecto.\n\nSe aconseja a los usuarios actualizar a Apache Log4j Core 2.25.4, que corrige este problema."}], "lastModified": "2026-10-26T22:10:00.163", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:apache:log4j:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "2C60BA8E-5300-45BD-AB82-2B8AD28917CD", "versionEndExcluding": "2.25.4", "versionStartIncluding": "2.12.0"}, {"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"}, {"criteria": "cpe:2.3:a:apache:log4j:3.0.0:beta3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "74C9FCBD-ECAD-4C29-B97A-2B9D97C0FC1F"}], "operator": "OR"}]}], "sourceIdentifier": "security@apache.org"}