CVE-2026-40021
mediumPriorität · verfolgen · 21EPSS 0.008 · 55. PerzentilDEEUUSEPSS · bewertet 2026-10-27
Apache Log4net's XmlLayout https://logging.apache.org/log4net/manual/configuration/layouts.html#layout-list and XmlLayoutSchemaLog4J https://logging.apache.org/log4net/manual/configuration/layouts.html#layout-list , in versions before 3.3.0, fail to sanitize characters forbidden by the XML 1.0 specification https://www.w3.org/TR/xml/#charsets in MDC property keys and values, as well as the identity field that may carry attacker-influenced data. This causes an exception during serialization and the silent loss of the affected log event. An attacker who can influence any of these fields can exploit this to suppress individual log records, impairing audit trails and detection of malicious activity. Users are advised to upgrade to Apache Log4net 3.3.0, which fixes this issue.
cvss
Technischer Schweregrad, 0–10. Eine Zeile je Quelle.
Basiswert 0–10 · höher = schwerwiegender · Vektor überfahren zum Auflösen⚠ Quellen uneinig · low–medium · 1.7–6.3
SSVC
Eine Handlungsentscheidung — aus Ausnutzung und Auswirkung.
schwächen
Die CWE-Schwächeklassen, zu denen dies gehört.
betroffene Produkte (5)
Betroffene Produkte und Versionsbereiche.
Advisories (2)
Hersteller- und Ökosystem-Meldungen dazu.
- WID-SEC-W-2026-1054Apache log4net: Schwachstelle ermöglicht Manipulation von DateienDeutsch2026-04-12csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Apache log4net ausnutzen, um Dateien zu manipulieren.
- GHSA-4f7c-pmjv-c25wApache Log4net: Silent log event loss in XmlLayout and XmlLayoutSchemaLog4J due to unescaped XML 1.0 forbidden characters2026-04-10ghsa · osvUS
Apache Log4net's XmlLayout https://logging.apache.org/log4net/manual/configuration/layouts.html#layout-list and XmlLayoutSchemaLog4J https://logging.apache.org/log4net/manual/configuration/layouts.html#layout-list , in versions before 3.3.0, fail to sanitize characters forbidden by the XML 1.0 specification https://www.w3.org/TR/xml/#charsets in MDC property keys and values, as well as the identity field that may carry attacker-influenced data. This causes an exception during serialization and the silent loss of the affected log event. An attacker who can influence any of these fields can exploit this to suppress individual log records, impairing audit trails and detection of malicious activity. Users are advised to upgrade to Apache Log4net 3.3.0, which fixes this issue.
auch bekannt als (3)
Weitere Namen und Kennungen dieser Entität.
quellen
Welche Quellen diesen Datensatz belegen und wann.
Referenzen (18)
Externe Belege — Patches, Meldungen, Analysen.
- http://www.openwall.com/lists/oss-security/2026/04/10/11cnnvd
- https://github.com/apache/logging-log4net/pull/280cnnvd
- https://lists.apache.org/thread/q8otftjswhk69n3kxslqg7cobr0x4st7cnnvd
- https://logging.apache.org/cyclonedx/vdr.xmlcnnvd
- https://logging.apache.org/log4net/download.htmlPatchcnnvd
- https://logging.apache.org/log4net/manual/configuration/layouts.htmlcnnvd
- https://logging.apache.org/security.html#CVE-2026-40021cnnvd
- https://github.com/apache/logging-log4net/pull/280enisa_euvd
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