5.3

CVE-2026-105243

Apache log4net: Oversize EventLogAppender record silently discarded

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.
Daten sind bereitgestellt durch das CVE Programm von einer CVE Numbering Authority (CNA) (Unstrukturiert).
HerstellerApache Software Foundation
≫
Produkt Apache log4net
Default Statusunaffected
Version 1.2.9
Version < 3.5.0
Status affected
HerstellerApache Software Foundation
≫
Produkt Apache log4net
Default Statusunaffected
Version 02e1e115435888485f2e28b414d267e39e799e07
Version < 28fbfb25678c48a8cc5bc9b94ead0dddfc39ffed
Status affected
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.33% 0.242
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
Apache 5.3 3.9 1.4
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
CWE-778 Insufficient Logging

When a security-critical event occurs, the product either does not record the event or omits important details about the event when logging it.

https://github.com/apache/logging-log4net/pull/315
https://github.com/apache/logging-log4net/commit/28fbfb25678c48a8cc5bc9b94ead0dddfc39ffed
https://lists.apache.org/thread.html/jr6fj5skv1vnjbc9jmt8bp151p8ow1rp
http://www.openwall.com/lists/oss-security/2026/10/07/17