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CVE PROGRAM SOURCE RECORD5.3 Medium

CVE-2026-105239

Apache log4net: NUL character truncates EventLogAppender records

Description

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Apache Software Foundation Apache log4net

Default version status: unaffected

  • 1.2.9 to < 3.5.0affected
pkg:nuget/log4net

Apache Software Foundation Apache log4net

Default version status: unaffected

  • 02e1e115435888485f2e28b414d267e39e799e07 to < dc5855a0720c91590fd7a81d729ea01fdd69e000affected
pkg:nuget/log4net

References