Improper Neutralization of Null Byte or NUL Character vulnerability in the OutputDebugStringAppender of Apache log4net.
A NUL character in logged content ended the debug output record at that point, so everything the layout rendered after it, including exception text and trailing fields, was silently lost. A party whose data reaches a log message could hide the rest of that record. Only applications on Windows that use OutputDebugStringAppender 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.
Metrics
Affected Vendors & Products
References
History
Fri, 09 Oct 2026 16:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| CPEs | cpe:2.3:a:apache:log4net:*:*:*:*:*:*:*:* |
Thu, 08 Oct 2026 07:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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Wed, 07 Oct 2026 07:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
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Wed, 07 Oct 2026 02:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Apache
Apache log4net |
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| Vendors & Products |
Apache
Apache log4net |
Tue, 06 Oct 2026 20:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Improper Neutralization of Null Byte or NUL Character vulnerability in the OutputDebugStringAppender of Apache log4net. A NUL character in logged content ended the debug output record at that point, so everything the layout rendered after it, including exception text and trailing fields, was silently lost. A party whose data reaches a log message could hide the rest of that record. Only applications on Windows that use OutputDebugStringAppender 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. | |
| Title | Apache log4net: NUL character truncates OutputDebugStringAppender records | |
| Weaknesses | CWE-158 | |
| References |
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| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: apache
Published: 2026-10-06T19:47:44.900Z
Updated: 2026-10-07T16:27:16.989Z
Reserved: 2026-10-04T16:20:07.533Z
Link: CVE-2026-105240
Updated: 2026-10-07T06:11:56.396Z
Status : Analyzed
Published: 2026-10-06T20:17:15.777
Modified: 2026-10-09T15:41:47.250
Link: CVE-2026-105240
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