Apache log4net: Request validation failure drops the event in the aspnet-request converter
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.
CVE-2026-105242
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-105242
Apache log4net
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Apache log4net
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "Apache Software Foundation",
"product": "Apache log4net",
"versions": [
{
"status": "affected",
"version": "1.2.11",
"lessThan": "3.5.0",
"versionType": "semver"
}
],
"packageURL": "pkg:nuget/log4net",
"packageName": "log4net",
"collectionURL": "https://nuget.org/packages",
"defaultStatus": "unaffected"
},
{
"repo": "https://gitbox.apache.org/repos/asf/logging-log4net.git",
"vendor": "Apache Software Foundation",
"product": "Apache log4net",
"versions": [
{
"status": "affected",
"version": "243f1e9f3ee235955bade4b4fe664a903378719a",
"lessThan": "145203420c579a703008b4b723b6a080757f4964",
"versionType": "git"
}
],
"packageURL": "pkg:nuget/log4net",
"packageName": "log4net",
"collectionURL": "https://nuget.org/packages",
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-105242
Source reference:
/cveMetadata/cveId
Publisher severity
medium
Source reference: /containers/cna/metrics
- Event
- #11884 · Revision 1
- Added to Heist Feed
- Publisher date