Apache Log4j 2.0-alpha1 < 2.25.4 XmlLayout Invalid XML Output (CVE-2026-34480)

The version of Apache Log4j on the remote host is 2.0-alpha1 through 2.25.3. It is, therefore, affected by a vulnerability: - The XmlLayout fails to sanitize characters forbidden by the XML 1.0 specification, producing invalid XML output whenever a log message or MDC value contains such character...

SUSE 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-2026-34480

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...

Linux Distros Unpatched Vulnerability : CVE-2026-40023

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - Apache Log4cxx's XMLLayout https://logging.apache.org/log4cxx/1.7.0/classlog4cxx11xml11XMLLayout.html , in versions before 1.7.0, fails to sanitize characters...

Apache Log4net: Silent log event loss in XmlLayout and XmlLayoutSchemaLog4J due to unescaped XML 1.0 forbidden characters

Apache Log4net's XmlLayout https://logging.apache.org/log4net/manual/configuration/layouts.htmllayout-list and XmlLayoutSchemaLog4J https://logging.apache.org/log4net/manual/configuration/layouts.htmllayout-list , in versions before 3.3.0, fail to sanitize characters forbidden by the XML 1.0...

Apache Log4j Core: Silent log event loss in XmlLayout due to unescaped XML 1.0 forbidden characters

Apache Log4j Core's XmlLayout, in versions up to and including 2.25.3, fails to sanitize characters forbidden by the XML 1.0 specification, producing invalid XML output whenever a log message or MDC value contains such characters. The impact depends on the StAX implementation in use: JRE built-in...

GHSA-3PXV-7CMR-FJR4 Apache Log4j Core: Silent log event loss in XmlLayout due to unescaped XML 1.0 forbidden characters

Apache Log4j Core's XmlLayout, in versions up to and including 2.25.3, fails to sanitize characters forbidden by the XML 1.0 specification, producing invalid XML output whenever a log message or MDC value contains such characters. The impact depends on the StAX implementation in use: JRE built-in...

Improper Encoding or Escaping of Output

Overview org.apache.logging.log4j:log4j-core is a logging library for Java. Affected versions of this package are vulnerable to Improper Encoding or Escaping of Output in the XmlLayout plugin. An attacker can cause log events to be silently lost or malformed by injecting XML 1.0 forbidden...

DEBIAN-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-2026-40023

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-2026-40023

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-2026-40023 Apache Log4cxx, Apache Log4cxx (Conan), Apache Log4cxx (Brew): Silent log event loss in XMLLayout due to unescaped XML 1.0 forbidden characters

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...

PT-2026-31942

Name of the Vulnerable Software and Affected Versions Apache Log4j Core versions up to and including 2.25.3 Description Apache Log4j Core's XmlLayout fails to sanitize characters forbidden by the XML 1.0 specification, resulting in invalid XML output when log messages or MDC values contain such...

PT-2026-31983

Name of the Vulnerable Software and Affected Versions Apache Log4cxx versions prior to 1.7.0 Description Apache Log4cxx's XMLLayout fails to sanitize characters forbidden by the XML 1.0 specification in log messages, NDC, and MDC property keys and values, resulting in invalid XML output. This can...

Apache Log4cxx 安全漏洞

Apache Log4cxx is a C++ logging framework developed by the Apache Foundation, based on the Apache log4j framework. Versions of Apache Log4cxx prior to 1.7.0 contained security vulnerabilities. These vulnerabilities stemmed from XMLLayout not clearing characters prohibited by the XML 1.0...