Bug 2547114 (CVE-2026-105239) - CVE-2026-105239 log4net-windows: log4net: Log record truncation via null byte in EventLogAppender
Summary: CVE-2026-105239 log4net-windows: log4net: Log record truncation via null byte...
Keywords:
Status: NEW
Alias: CVE-2026-105239
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-10-06 19:54 UTC by OSIDB Bzimport
Modified: 2026-10-07 10:37 UTC (History)
0 users

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:

Attachments (Terms of Use)

Description OSIDB Bzimport 2026-10-06 19:54:19 UTC 
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.
Note You need to log in before you can comment on or make changes to this bug.