CVE-2026-105242
mediumpriority · track · 0EPSS 0.008 · 57 %ileDEUSEPSS · scored 2026-10-26
Improper Handling of Exceptional Conditions vulnerability in the aspnet-request pattern converter of Apache log4net. Reading request parameters triggers ASP.NET request validation, so a request carrying content such as markup made the layout throw and the appender discarded the whole event. A sender could suppress the log record of their own request. Only applications on ASP.NET for .NET Framework whose layout uses %aspnet-request are affected. This issue affects Apache log4net: from 1.2.11 before 3.5.0. Users are recommended to upgrade to version 3.5.0, which fixes the issue.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (3)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-3772Apache log4net: Mehrere Schwachstellen ermöglichen Manipulation von DateienDeutsch2026-10-06csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Apache log4net ausnutzen, um Dateien zu manipulieren.
sources
Which sources assert this record, and when.
references (4) nvd
External citations — patches, advisories, analysis.
- http://www.openwall.com/lists/oss-security/2026/10/07/16Mailing ListThird Party Advisory
- https://github.com/apache/logging-log4net/commit/145203420c579a703008b4b723b6a080757f4964Patch
- https://github.com/apache/logging-log4net/pull/316Patch
- https://lists.apache.org/thread.html/zg6dbqm4ztm7j3c21nfsqj0yxm5yrpdxMailing ListVendor Advisory
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