CVE-2026-34479
Gravedad CVSS v4.0:
MEDIA
Tipo:
No Disponible / Otro tipo
Fecha de publicación:
10/04/2026
Última modificación:
10/04/2026
Descripción
*** Pendiente de traducción *** 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 processing systems to drop or fail to index affected records.<br />
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Two groups of users are affected:<br />
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* Those using Log4j1XmlLayout directly in a Log4j Core 2 configuration file.<br />
* Those using the Log4j 1 configuration compatibility layer with org.apache.log4j.xml.XMLLayout specified as the layout class.<br />
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Users are advised to upgrade to Apache Log4j 1-to-Log4j 2 bridge version 2.25.4, which corrects this issue.<br />
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Note: The Apache Log4j 1-to-Log4j 2 bridge is deprecated and will not be present in Log4j 3. Users are encouraged to consult the Log4j 1 to Log4j 2 migration guide https://logging.apache.org/log4j/2.x/migrate-from-log4j1.html , and specifically the section on eliminating reliance on the bridge.
Impacto
Puntuación base 4.0
6.90
Gravedad 4.0
MEDIA
Referencias a soluciones, herramientas e información
- https://github.com/apache/logging-log4j2/pull/4078
- https://lists.apache.org/thread/gd0hp6mj17rn3kj279vgy4p7kd4zz5on
- https://logging.apache.org/cyclonedx/vdr.xml
- https://logging.apache.org/log4j/2.x/migrate-from-log4j1.html
- https://logging.apache.org/security.html#CVE-2026-34479
- http://www.openwall.com/lists/oss-security/2026/04/10/8