{"id":"CVE-2026-105240","title":"Improper Neutralization of Null Byte or NUL Character vulnerability in the OutputDebugStringAppender of Apache log4net.\n\nA NUL character in logged content ended the debug output record at that point, so everything the layout rendered aft…","summary":"Improper Neutralization of Null Byte or NUL Character vulnerability in the OutputDebugStringAppender of Apache log4net.\n\nA NUL character in logged content ended the debug output record at that point, so everything the layout rendered aft…","severity":"medium","cvss":5.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","cwe":["CWE-158"],"vendor":"Apache Software Foundation","product":"log4net","affected":["log4net >= 1.2.9 < 3.5.0","log4net >= 02e1e115435888485f2e28b414d267e39e799e07 < 6046fe9d7f353b49fe995361c071ec2eea8f7ef6"],"published":"2026-10-06","updated":"2026-10-06","sourceUpdated":"2026-10-06T20:17:15.777","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-105240","references":[{"url":"https://github.com/apache/logging-log4net/commit/6046fe9d7f353b49fe995361c071ec2eea8f7ef6","label":"security@apache.org"},{"url":"https://github.com/apache/logging-log4net/pull/315","label":"security@apache.org"},{"url":"https://lists.apache.org/thread.html/gyw2d4ppy82t1vlpdknkfd1nmzp21z17","label":"security@apache.org"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-10-06T20:16:42.480Z","slug":"CVE-2026-105240","body":"## Overview\n\nImproper Neutralization of Null Byte or NUL Character vulnerability in the OutputDebugStringAppender of Apache log4net.\n\nA NUL character in logged content ended the debug output record at that point, so everything the layout rendered after it, including exception text and trailing fields, was silently lost. A party whose data reaches a log message could hide the rest of that record. Only applications on Windows that use OutputDebugStringAppender 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":29,"depthScoreParts":{"impact":29.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}