CVE catalog
CVE-2026-105243
DEBIAN-CVE-2026-105243
- Severity
- Unknown
- Published
- Updated
- Source
- [NVD] · [CVE record]
- EPSS
- 0.81% · Oct 25, 2026
Insufficient Logging vulnerability in the EventLogAppender of Apache log4net. Long messages were truncated to a fixed size that exceeds what the Windows Event Log accepts once the log and source names are counted, and the event log then stored nothing and reported nothing. A party whose data reaches a log message could suppress the whole record by making it long enough. Only applications on Windows that use EventLogAppender 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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | log4net | 13 | 1.2.10+dfsg-10 | vulnerable |
| Debian | log4net | 13 | 1.2.10+dfsg-9 | vulnerable |
| Debian | log4net | 14 | 1.2.10+dfsg-10 | vulnerable |
| Debian | log4net | 14 | 1.2.10+dfsg-9 | vulnerable |
Fixed-version evidence
OpenFactory catalog packages
[Debian 13 (Trixie)]
- [liblog4net1.2-cil]Affected
Source package: [log4net]
Details (2)
1.2.10+dfsg-9· all · trixieAffected
pypi · log4net · debian · 13
1.2.10+dfsg-9· all · trixieAffected
pypi · log4net · debian · 13
- [liblog4net-cil-dev]Affected
Source package: [log4net]
Details (2)
1.2.10+dfsg-9· all · trixieAffected
pypi · log4net · debian · 13
1.2.10+dfsg-9· all · trixieAffected
pypi · log4net · debian · 13
Observed: