CVE-2026-105241
published 2026-10-06CVE-2026-105241: Improper Handling of Unicode Encoding vulnerability in the SmtpPickupDirAppender of Apache log4net. Content that the mail file writer cannot encode, such as an…
PriorityP431medium5.3CVSS 3.1
AVNACLPRNUINSUCNILAN
EPSS
0.82%
57.1th percentile
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.
Affected
3 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| apache | log4net | >= 1.2.9 < 3.5.0 | 3.5.0 |
| apache_software_foundation | apache_log4net | >= 02e1e115435888485f2e28b414d267e39e799e07 < 4d2e10f0908199604b4326f9df6d0b43b871e333 | 4d2e10f0908199604b4326f9df6d0b43b871e333 |
| apache_software_foundation | apache_log4net | >= 1.2.9 < 3.5.0 | 3.5.0 |
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Bugzilla
CVE-2026-105241 log4net: log4net: Log event suppression via improper Unicode handling in SmtpPickupDirAppender [epel-all]
bugzilla·2026-10-07·CVSS 5.3
CVE-2026-105241 [MEDIUM] CVE-2026-105241 log4net: log4net: Log event suppression via improper Unicode handling in SmtpPickupDirAppender [epel-all]
CVE-2026-105241 log4net: log4net: Log event suppression via improper Unicode handling in SmtpPickupDirAppender [epel-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
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 appl
Bugzilla
CVE-2026-105241 log4net: log4net: Log event suppression via improper Unicode handling in SmtpPickupDirAppender [fedora-all]
bugzilla·2026-10-07·CVSS 5.3
CVE-2026-105241 [MEDIUM] CVE-2026-105241 log4net: log4net: Log event suppression via improper Unicode handling in SmtpPickupDirAppender [fedora-all]
CVE-2026-105241 log4net: log4net: Log event suppression via improper Unicode handling in SmtpPickupDirAppender [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
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 ap
Bugzilla
CVE-2026-105241 log4net: log4net: Log event suppression via improper Unicode handling in SmtpPickupDirAppender
bugzilla·2026-10-06·CVSS 5.3
CVE-2026-105241 [MEDIUM] CVE-2026-105241 log4net: log4net: Log event suppression via improper Unicode handling in SmtpPickupDirAppender
CVE-2026-105241 log4net: log4net: Log event suppression via improper Unicode handling in SmtpPickupDirAppender
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.
2026-10-06
Published