Improper Encoding or Escaping of Output

Overview Affected versions of this package are vulnerable to Improper Encoding or Escaping of Output in the XmlLayout and XmlLayoutSchemaLog4J layouts due to improper sanitisation of unescaped XML 1.0 forbidden characters in MDC property keys, values, or the identity field. An attacker can cause...

EUVD-2026-21498

In systemd 259, systemd-journald can send ANSI escape sequences to the terminals of arbitrary users when a "logger -p emerg" command is executed, if ForwardToWall=yes is set...

Apache Log4j Core: log injection in `Rfc5424Layout` due to silent configuration incompatibility

Apache Log4j Core's Rfc5424Layout, in versions 2.21.0 through 2.25.3, is vulnerable to log injection via CRLF sequences due to undocumented renames of security-relevant configuration attributes. Two distinct issues affect users of stream-based syslog services who configure Rfc5424Layout directly:...

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 Log4j1XmlLayout plugin. An attacker can cause log events to be silently lost or downstream log processing systems to drop ...

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...

CVE-2026-40228

In systemd 259, systemd-journald can send ANSI escape sequences to the terminals of arbitrary users when a "logger -p emerg" command is executed, if ForwardToWall=yes is set...

CVE-2026-40021

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...

CVE-2026-40021

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...

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

CVE-2026-40023 concerns Apache Log4cxx XMLLayout (pre-1.7.0) that fails to sanitize XML 1.0 forbidden characters in log messages, NDC, and MDC keys/values, producing invalid XML. Conforming parsers may reject such documents, potentially dropping or failing to index affected records and impairing ...

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...

CVE-2026-40021 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...

CVE-2026-40021

Apache Log4net before version 3.3.0 contains a vulnerability in XmlLayout and XmlLayoutSchemaLog4J where characters forbidden by XML 1.0 are not sanitized in MDC keys/values and the identity field. The issue causes a serialization exception and silent loss of the affected log event, which can be ...

CVE-2026-40021 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...

CVE-2026-40021

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...

CVE-2026-40021

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...

CVE-2026-34480

Technical details about CVE-2026-34480 are not publicly available in the provided connected documents. The initial description gives an overview but no vendor/product/version specifics or remediation steps here. Monitor for updates from official advisories.

CVE-2026-34480 Apache Log4j Core: Silent log event loss in XmlLayout due to unescaped XML 1.0 forbidden characters

Apache Log4j Core's XmlLayout https://logging.apache.org/log4j/2.x/manual/layouts.htmlXmlLayout , in versions up to and including 2.25.3, fails to sanitize characters forbidden by the XML 1.0 specification https://www.w3.org/TR/xml/charsets producing invalid XML output whenever a log message or M...

CVE-2026-34479 Apache Log4j 1 to Log4j 2 bridge: Silent log event loss in Log4j1XmlLayout due to unescaped XML 1.0 forbidden characters

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...