{"resultsPerPage":1,"startIndex":0,"totalResults":1,"format":"NVD_CVE","version":"2.0","timestamp":"2026-06-10T19:32:33.207","vulnerabilities":[{"cve":{"id":"CVE-2026-34479","sourceIdentifier":"security@apache.org","published":"2026-04-10T16:16:31.270","lastModified":"2026-05-06T18:21:34.373","vulnStatus":"Analyzed","cveTags":[],"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."}],"metrics":{"cvssMetricV40":[{"source":"security@apache.org","type":"Secondary","cvssData":{"version":"4.0","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","baseScore":6.9,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"LOW","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}}],"cvssMetricV31":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"NONE"},"exploitabilityScore":3.9,"impactScore":3.6}]},"weaknesses":[{"source":"security@apache.org","type":"Secondary","description":[{"lang":"en","value":"CWE-116"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:apache:log4j:*:*:*:*:*:*:*:*","versionStartIncluding":"2.7","versionEndExcluding":"2.25.4","matchCriteriaId":"4D7C1729-01D6-4981-B3FB-3A877083AE28"},{"vulnerable":true,"criteria":"cpe:2.3:a:apache:log4j:3.0.0:alpha1:*:*:*:*:*:*","matchCriteriaId":"5EE518C3-2F43-40FF-B754-C340B7003FC7"},{"vulnerable":true,"criteria":"cpe:2.3:a:apache:log4j:3.0.0:alpha1_rc1:*:*:*:*:*:*","matchCriteriaId":"6D2A01C1-D56C-4198-8ADB-11739F791E2B"},{"vulnerable":true,"criteria":"cpe:2.3:a:apache:log4j:3.0.0:alpha1_rc2:*:*:*:*:*:*","matchCriteriaId":"D6F8BD61-DD30-4D64-842C-850E5B117036"},{"vulnerable":true,"criteria":"cpe:2.3:a:apache:log4j:3.0.0:beta1:*:*:*:*:*:*","matchCriteriaId":"ED00C38D-27EA-489C-9A2B-3594ACA8A3C5"},{"vulnerable":true,"criteria":"cpe:2.3:a:apache:log4j:3.0.0:beta2:*:*:*:*:*:*","matchCriteriaId":"8794D719-1D90-4378-B48B-698EA40FBFB2"}]}]}],"references":[{"url":"https://github.com/apache/logging-log4j2/pull/4078","source":"security@apache.org","tags":["Exploit","Issue Tracking","Patch"]},{"url":"https://lists.apache.org/thread/gd0hp6mj17rn3kj279vgy4p7kd4zz5on","source":"security@apache.org","tags":["Mailing List"]},{"url":"https://logging.apache.org/cyclonedx/vdr.xml","source":"security@apache.org","tags":["Vendor Advisory"]},{"url":"https://logging.apache.org/log4j/2.x/migrate-from-log4j1.html","source":"security@apache.org","tags":["Mitigation"]},{"url":"https://logging.apache.org/security.html#CVE-2026-34479","source":"security@apache.org","tags":["Vendor Advisory"]},{"url":"http://www.openwall.com/lists/oss-security/2026/04/10/8","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Mailing List"]}]}}]}