5.3

CVE-2026-105239

Apache log4net: NUL character truncates EventLogAppender records

Improper Neutralization of Null Byte or NUL Character vulnerability in the EventLogAppender of Apache log4net.

A NUL character in logged content ended the Windows Event Log record at that point, so everything the layout rendered after it, including exception text and trailing fields, was silently not stored. A party whose data reaches a log message could hide the rest of that record. Only applications on Windows that use EventLogAppender are affected.

This issue affects Apache log4net: from 1.2.9 before 3.5.0.

Users are recommended to upgrade to version 3.5.0, which fixes the issue.
Daten sind bereitgestellt durch das CVE Programm von einer CVE Numbering Authority (CNA) (Unstrukturiert).
HerstellerApache Software Foundation
≫
Produkt Apache log4net
Default Statusunaffected
Version 1.2.9
Version < 3.5.0
Status affected
HerstellerApache Software Foundation
≫
Produkt Apache log4net
Default Statusunaffected
Version 02e1e115435888485f2e28b414d267e39e799e07
Version < dc5855a0720c91590fd7a81d729ea01fdd69e000
Status affected
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.34% 0.251
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
Apache 5.3 3.9 1.4
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
CWE-158 Improper Neutralization of Null Byte or NUL Character

The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes NUL characters or null bytes when they are sent to a downstream component.

https://github.com/apache/logging-log4net/pull/315
https://github.com/apache/logging-log4net/commit/dc5855a0720c91590fd7a81d729ea01fdd69e000
https://lists.apache.org/thread.html/9fx1qo5hc0tg8ym0t6p9gt1zpb2qlxpq
http://www.openwall.com/lists/oss-security/2026/10/07/14