CVE-2026-105242
mediumImproper Handling of Exceptional Conditions vulnerability in the aspnet-request pattern converter of Apache log4net.
Vendor / product: Apache — log4net
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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Affected products
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
References
- https://github.com/apache/logging-log4net/commit/145203420c579a703008b4b723b6a080757f4964 security@apache.org
- https://github.com/apache/logging-log4net/pull/316 security@apache.org
- https://lists.apache.org/thread.html/zg6dbqm4ztm7j3c21nfsqj0yxm5yrpdx security@apache.org
- http://www.openwall.com/lists/oss-security/2026/10/07/16 af854a3a-2127-422b-91ae-364da2661108