5.3

CVE-2026-105241

Apache log4net: Unencodable content discards a whole SmtpPickupDirAppender batch

Improper Handling of Unicode Encoding vulnerability in the SmtpPickupDirAppender of Apache log4net.

Content that the mail file writer cannot encode, such as an unpaired UTF-16 surrogate, made the write throw. Every buffered event in the batch was discarded, not only the one carrying the content, and a truncated mail could be left in the pickup directory. A party whose data reaches a log message could suppress the records of other events. Only applications that use SmtpPickupDirAppender 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 < 4d2e10f0908199604b4326f9df6d0b43b871e333
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 0.34% 0.251
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-176 Improper Handling of Unicode Encoding

The product does not properly handle when an input contains Unicode encoding.

https://github.com/apache/logging-log4net/pull/315
https://github.com/apache/logging-log4net/commit/4d2e10f0908199604b4326f9df6d0b43b871e333
https://lists.apache.org/thread.html/hg8dgh3oy8bp3dhb8nsygk9kw2o401ws
http://www.openwall.com/lists/oss-security/2026/10/07/15