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CVE-2026-40023

Apache Log4cxx's XMLLayout https://logging.apache.org/log4cxx/1.7.0/classlog4cxx_1_1xml_1_1XMLLayout.html , in versions before 1.7.0, fails to sanitize characters forbidden by the XML 1.0 specification https://www.w3.org/TR/xml/#charsets in log messages, NDC, and MDC property keys and values, producing invalid XML output. Conforming XML parsers must reject such documents with a fatal error, which may cause downstream log processing systems to drop or fail to index affected records. An attack
Lifecycle PUBLISHED1 preserved revisionFact urn:baitaphish:canonical-cve-fact-revision:v2:c8312cffefac8e79fcce548245d0fc84ac85e3469614d82812e3cc7bcbedd48f
Known exploited
Not asserted
Disputed
No
Stale source
No
Conflicts
1

Preserved source conflicts

No provider value was silently selected as the winner.

affected · 3 assertions

{"cpes":["cpe:2.3:a:apache:log4cxx:*:*:*:*:*:*:*:*"],"defaultStatus":"unaffected","product":"Apache Log4cxx","vendor":"Apache Software Foundation","versions":[{"lessThan":"1.7.0","status":"affected","version":"0","versionType":"semver"}]}

  • cve_program_cvelist_v5affected
    urn:baitaphish:normalized-source-record:v2:0023953ed5c74fa9c5418a3cd0ab72931b8189386714811c18b30da7caf92548 · sha256:61c78436dbdc4c6f… · /containers/cna/affected/0

{"collectionURL":"https://conan.io/center","defaultStatus":"unaffected","packageName":"log4cxx","packageURL":"pkg:conan/log4cxx","product":"Apache Log4cxx (Conan)","vendor":"Apache Software Foundation","versions":[{"lessThan":"1.7.0","status":"affected","version":"0","versionType":"semver"}]}

  • cve_program_cvelist_v5affected
    urn:baitaphish:normalized-source-record:v2:0023953ed5c74fa9c5418a3cd0ab72931b8189386714811c18b30da7caf92548 · sha256:61c78436dbdc4c6f… · /containers/cna/affected/1

{"collectionURL":"https://brew.sh/","defaultStatus":"unaffected","packageName":"log4cxx","product":"Apache Log4cxx (Brew)","vendor":"Apache Software Foundation","versions":[{"lessThan":"1.7.0","status":"affected","version":"0","versionType":"semver"}]}

  • cve_program_cvelist_v5affected
    urn:baitaphish:normalized-source-record:v2:0023953ed5c74fa9c5418a3cd0ab72931b8189386714811c18b30da7caf92548 · sha256:61c78436dbdc4c6f… · /containers/cna/affected/2

Affected products and versions

3 source assertions
{"cpes":["cpe:2.3:a:apache:log4cxx:*:*:*:*:*:*:*:*"],"defaultStatus":"unaffected","product":"Apache Log4cxx","vendor":"Apache Software Foundation","versions":[{"lessThan":"1.7.0","status":"affected","version":"0","versionType":"semver"}]}
  • cve_program_cvelist_v5affected
    urn:baitaphish:normalized-source-record:v2:0023953ed5c74fa9c5418a3cd0ab72931b8189386714811c18b30da7caf92548 · sha256:61c78436dbdc4c6f… · /containers/cna/affected/0
{"collectionURL":"https://conan.io/center","defaultStatus":"unaffected","packageName":"log4cxx","packageURL":"pkg:conan/log4cxx","product":"Apache Log4cxx (Conan)","vendor":"Apache Software Foundation","versions":[{"lessThan":"1.7.0","status":"affected","version":"0","versionType":"semver"}]}
  • cve_program_cvelist_v5affected
    urn:baitaphish:normalized-source-record:v2:0023953ed5c74fa9c5418a3cd0ab72931b8189386714811c18b30da7caf92548 · sha256:61c78436dbdc4c6f… · /containers/cna/affected/1
{"collectionURL":"https://brew.sh/","defaultStatus":"unaffected","packageName":"log4cxx","product":"Apache Log4cxx (Brew)","vendor":"Apache Software Foundation","versions":[{"lessThan":"1.7.0","status":"affected","version":"0","versionType":"semver"}]}
  • cve_program_cvelist_v5affected
    urn:baitaphish:normalized-source-record:v2:0023953ed5c74fa9c5418a3cd0ab72931b8189386714811c18b30da7caf92548 · sha256:61c78436dbdc4c6f… · /containers/cna/affected/2

Provider-owned CVSS observations

1 source assertion
{"metric":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"HIGH","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":6.3,"baseSeverity":"MEDIUM","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"LOW","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"N…
  • cve_program_cvelist_v5cvss
    urn:baitaphish:normalized-source-record:v2:0023953ed5c74fa9c5418a3cd0ab72931b8189386714811c18b30da7caf92548 · sha256:61c78436dbdc4c6f… · /containers/cna/metrics/0/cvssV4_0

CWE assertions

1 source assertion
{"cweId":"CWE-116","description":"CWE-116 Improper Encoding or Escaping of Output","lang":"en","type":"CWE"}
  • cve_program_cvelist_v5cwe
    urn:baitaphish:normalized-source-record:v2:0023953ed5c74fa9c5418a3cd0ab72931b8189386714811c18b30da7caf92548 · sha256:61c78436dbdc4c6f… · /containers/cna/problemTypes/0/descriptions/0

Source references

6 source assertions
{"url":"http://www.openwall.com/lists/oss-security/2026/04/10/12"}
  • cve_program_cvelist_v5reference
    urn:baitaphish:normalized-source-record:v2:0023953ed5c74fa9c5418a3cd0ab72931b8189386714811c18b30da7caf92548 · sha256:61c78436dbdc4c6f… · /containers/adp/0/references/0
{"tags":["patch"],"url":"https://github.com/apache/logging-log4cxx/pull/609"}
  • cve_program_cvelist_v5reference
    urn:baitaphish:normalized-source-record:v2:0023953ed5c74fa9c5418a3cd0ab72931b8189386714811c18b30da7caf92548 · sha256:61c78436dbdc4c6f… · /containers/cna/references/0
{"tags":["vendor-advisory"],"url":"https://lists.apache.org/thread/y15cv3zblg3dfwr5vy6ddbnl4zyrzr8b"}
  • cve_program_cvelist_v5reference
    urn:baitaphish:normalized-source-record:v2:0023953ed5c74fa9c5418a3cd0ab72931b8189386714811c18b30da7caf92548 · sha256:61c78436dbdc4c6f… · /containers/cna/references/4
{"tags":["vendor-advisory"],"url":"https://logging.apache.org/cyclonedx/vdr.xml"}
  • cve_program_cvelist_v5reference
    urn:baitaphish:normalized-source-record:v2:0023953ed5c74fa9c5418a3cd0ab72931b8189386714811c18b30da7caf92548 · sha256:61c78436dbdc4c6f… · /containers/cna/references/2
{"tags":["related"],"url":"https://logging.apache.org/log4cxx/1.7.0/classlog4cxx_1_1xml_1_1XMLLayout.html"}
  • cve_program_cvelist_v5reference
    urn:baitaphish:normalized-source-record:v2:0023953ed5c74fa9c5418a3cd0ab72931b8189386714811c18b30da7caf92548 · sha256:61c78436dbdc4c6f… · /containers/cna/references/3
{"tags":["vendor-advisory"],"url":"https://logging.apache.org/security.html#CVE-2026-40023"}
  • cve_program_cvelist_v5reference
    urn:baitaphish:normalized-source-record:v2:0023953ed5c74fa9c5418a3cd0ab72931b8189386714811c18b30da7caf92548 · sha256:61c78436dbdc4c6f… · /containers/cna/references/1

Attribution and limitations

  • CVE Program CVEList V5: Reproduce the MITRE copyright designation and CVE license in copies. Source →

Provider severity values are preserved separately. Baitaphish does not convert them into a risk rating, infer affected products, or treat EPSS as observed exploitation.

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