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 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: 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-2026-34480 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-2026-34480 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-2026-34480

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-2026-34480 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-2026-34480

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-2026-34479 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...

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...

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...

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...

Qualys Security Advisory - CVE-2015-3245 userhelper - CVE-2015-3246 libuser

Hello, it is July 23, 2015, 17:00 UTC, the Coordinated Release Date for CVE-2015-3245 and CVE-2015-3246. Please find our advisory below, and our exploit attached. Qualys Security Advisory CVE-2015-3245 userhelper chfn newline filtering CVE-2015-3246 libuser passwd file handling -- Summary...