Improper Handling of Exceptional Conditions Affecting log4net package, versions *
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published7 Oct 2026
- disclosed6 Oct 2026
Introduced: 6 Oct 2026
NewCVE-2026-105242 (opens in a new tab)How to fix?
There is no fixed version for Echo:latest log4net.
NVD Description
Note: Versions mentioned in the description apply only to the upstream log4net package and not the log4net package as distributed by Echo.
See How to fix? for Echo:latest relevant fixed versions and status.
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.
References
- https://advisory.echohq.com/cve/CVE-2026-105242
- https://github.com/apache/logging-log4net/commit/145203420c579a703008b4b723b6a080757f4964
- https://github.com/apache/logging-log4net/pull/316
- https://lists.apache.org/thread.html/zg6dbqm4ztm7j3c21nfsqj0yxm5yrpdx
- http://www.openwall.com/lists/oss-security/2026/10/07/16