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CVE-2026-40023

Apache Log4cxx, Apache Log4cxx (Conan), Apache Log4cxx (Brew): Silent log event loss in XMLLayout due to unescaped XML 1.0 forbidden characters PUBLISHED

Description (CNA)

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 attacker who can influence logged data can exploit this to suppress individual log records, impairing audit trails and detection of malicious activity. Users are advised to upgrade to Apache Log4cxx 1.7.0, which fixes this issue.

Affected (CNA)

Vendor / productVersions
Apache Software Foundation / Apache Log4cxxaffected 0 before 1.7.0
Apache Software Foundation / Apache Log4cxx (Conan)affected 0 before 1.7.0
Apache Software Foundation / Apache Log4cxx (Brew)affected 0 before 1.7.0

CWE

CWE-116

References

ADP enrichment

CVE

No English description supplied.

CISA-ADP

No English description supplied.

No references supplied.