org.apache.logging.log4j/log4j-core: Apache Log4j Core: Invalid XML output causes denial of service in logging

A flaw was found in Apache Log4j Core. The XmlLayout component, responsible for formatting log messages into XML, does not properly remove or replace characters that are not allowed in XML 1.0. When log messages or diagnostic information contain these forbidden characters, the resulting XML outpu...

Security Bulletin: Due to use of log4j-core, IBM webMethods BPM is vulnerable to ImproperImproper Encoding or Escaping of Output

Summary IBM webMethods BPM is dependant on log4j-core which is affected by known vulnerability - CVE-2026-34480 Vulnerability Details CVEID:CVE-2026-34480 DESCRIPTION: Apache Log4j Core's XmlLayout https://logging.apache.org/log4j/2.x/manual/layouts.htmlXmlLayout , in versions up to and including...

org.apache.logging.log4j/log4j-core: Apache Log4j Core: Invalid XML output causes denial of service in logging

A flaw was found in Apache Log4j Core. The XmlLayout component, responsible for formatting log messages into XML, does not properly remove or replace characters that are not allowed in XML 1.0. When log messages or diagnostic information contain these forbidden characters, the resulting XML outpu...

CVE-2026-40023

Apache Log4cxx's XMLLayout https://logging.apache.org/log4cxx/1.7.0/classlog4cxx11xml11XMLLayout.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, producin...

CVE-2026-34479

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...

CVE-2026-40023

Apache Log4cxx's XMLLayout https://logging.apache.org/log4cxx/1.7.0/classlog4cxx11xml11XMLLayout.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, producin...