{"id":"CVE-2026-105241","revision":"d1cc784befc846fb896cfbe085092bda","records":[{"revision":"d1cc784befc846fb896cfbe085092bda","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-105241","aliases":[],"title":"Apache log4net: Unencodable content discards a whole SmtpPickupDirAppender batch","description":"Improper Handling of Unicode Encoding vulnerability in the SmtpPickupDirAppender of Apache log4net.\n\nContent 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.\n\nThis issue affects Apache log4net: from 1.2.9 before 3.5.0.\n\nUsers are recommended to upgrade to version 3.5.0, which fixes the issue.","state":0,"publishedAt":"2026-10-06T19:49:03.994+00:00","modifiedAt":"2026-10-07T14:45:58.074+00:00","affected":[{"ecosystem":"NuGet","name":"log4net","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"Apache Software Foundation\",\n                    \"product\": \"Apache log4net\",\n                    \"packageURL\": \"pkg:nuget/log4net\",\n                    \"versions\": [\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"1.2.9\",\n                            \"lessThan\": \"3.5.0\",\n                            \"versionType\": \"semver\"\n                        }\n                    ],\n                    \"defaultStatus\": \"unaffected\",\n                    \"collectionURL\": \"https://nuget.org/packages\",\n                    \"packageName\": \"log4net\"\n                }"},{"ecosystem":"NuGet","name":"log4net","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"Apache Software Foundation\",\n                    \"product\": \"Apache log4net\",\n                    \"packageURL\": \"pkg:nuget/log4net\",\n                    \"repo\": \"https://gitbox.apache.org/repos/asf/logging-log4net.git\",\n                    \"versions\": [\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"02e1e115435888485f2e28b414d267e39e799e07\",\n                            \"lessThan\": \"4d2e10f0908199604b4326f9df6d0b43b871e333\",\n                            \"versionType\": \"git\"\n                        }\n                    ],\n                    \"defaultStatus\": \"unaffected\",\n                    \"collectionURL\": \"https://nuget.org/packages\",\n                    \"packageName\": \"log4net\"\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","score":5.3,"severity":"MEDIUM"}],"references":["https://github.com/apache/logging-log4net/pull/315","https://github.com/apache/logging-log4net/commit/4d2e10f0908199604b4326f9df6d0b43b871e333","https://lists.apache.org/thread.html/hg8dgh3oy8bp3dhb8nsygk9kw2o401ws"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-105241","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-105241","identifiers":["CVE-2026-105241"]},"retained":false,"historicalAffected":[]}],"coverage":[]}