{"schema_version":1,"title":"Apache Log4net vulnerabilities","summary":"Junglewise Threat Intelligence has tracked 7 vulnerabilities in Apache Log4net: 0 in the last 7 days and 6 in the last 90 days, 0 of them critical and 0 exploited in the wild. The most recent, CVE-2026-105244, was published on 6 October 2026. Nothing in the last four weeks, down from 6 vulnerabilities in the four before.","url":"https://junglewise.ai/threats/technologies/log4net","json_url":"https://junglewise.ai/threats/technologies/log4net.json","publisher":"Junglewise Threat Intelligence","license":"CC-BY-4.0","license_url":"https://creativecommons.org/licenses/by/4.0/","attribution":"Junglewise Threat Intelligence, https://junglewise.ai/threats/technologies/log4net","sources":"NVD, GitHub Security Advisories, OSV, the CISA Known Exploited Vulnerabilities catalog, FIRST EPSS and vendor advisories","kind":"technology","thin":false,"counts":{"high":0,"all_time":7,"critical":0,"exploited":0,"last_7_days":0,"last_30_days":0,"last_90_days":6,"last_365_days":7},"latest":[{"cve":"CVE-2026-105244","cvss":5.3,"slug":"cve-2026-105244-improper-encoding-or-escaping-of-output-vulnerability-in-the","title":"Apache log4net improper character escaping in RemoteSyslogAppender","severity":"medium","exploited":false,"published_at":"2026-10-06T20:17:16.297+00:00","url":"https://junglewise.ai/threats/cve-2026-105244-improper-encoding-or-escaping-of-output-vulnerability-in-the"},{"cve":"CVE-2026-105243","cvss":5.3,"slug":"cve-2026-105243-insufficient-logging-vulnerability-in-the-eventlogappender-of","title":"Apache log4net insufficient logging in EventLogAppender","severity":"medium","exploited":false,"published_at":"2026-10-06T20:17:16.167+00:00","url":"https://junglewise.ai/threats/cve-2026-105243-insufficient-logging-vulnerability-in-the-eventlogappender-of"},{"cve":"CVE-2026-105242","cvss":5.3,"slug":"cve-2026-105242-improper-handling-of-exceptional-conditions-vulnerability-in-the","title":"Apache log4net improper handling of exceptions in aspnet-request pattern converter","severity":"medium","exploited":false,"published_at":"2026-10-06T20:17:16.037+00:00","url":"https://junglewise.ai/threats/cve-2026-105242-improper-handling-of-exceptional-conditions-vulnerability-in-the"},{"cve":"CVE-2026-105241","cvss":5.3,"slug":"cve-2026-105241-improper-handling-of-unicode-encoding-vulnerability-in-the","title":"Apache log4net improper Unicode encoding in SmtpPickupDirAppender","severity":"medium","exploited":false,"published_at":"2026-10-06T20:17:15.907+00:00","url":"https://junglewise.ai/threats/cve-2026-105241-improper-handling-of-unicode-encoding-vulnerability-in-the"},{"cve":"CVE-2026-105240","cvss":5.3,"slug":"cve-2026-105240-improper-neutralization-of-null-byte-or-nul-character","title":"Apache log4net null byte handling in OutputDebugStringAppender","severity":"medium","exploited":false,"published_at":"2026-10-06T20:17:15.777+00:00","url":"https://junglewise.ai/threats/cve-2026-105240-improper-neutralization-of-null-byte-or-nul-character"},{"cve":"CVE-2026-105239","cvss":5.3,"slug":"cve-2026-105239-improper-neutralization-of-null-byte-or-nul-character","title":"Apache log4net null byte injection in EventLogAppender","severity":"medium","exploited":false,"published_at":"2026-10-06T20:17:15.63+00:00","url":"https://junglewise.ai/threats/cve-2026-105239-improper-neutralization-of-null-byte-or-nul-character"},{"cve":"CVE-2026-40021","cvss":5.3,"epss":0.0098,"slug":"cve-2026-40021-apache-log4net-log-suppression-in-xmllayout","title":"Apache Log4net log suppression in XmlLayout","severity":"medium","exploited":false,"published_at":"2026-04-10T16:16:32.42+00:00","url":"https://junglewise.ai/threats/cve-2026-40021-apache-log4net-log-suppression-in-xmllayout"}],"weekly":[{"week":"2026-08-17","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-08-24","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-08-31","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-09-07","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-09-14","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-09-21","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-09-28","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-10-05","critical":0,"exploited":0,"vulnerabilities":6},{"week":"2026-10-12","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-10-19","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-10-26","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-11-02","critical":0,"exploited":0,"vulnerabilities":0},{"week":"2026-11-09","critical":0,"exploited":0,"vulnerabilities":0}],"related":[{"name":"Apache Airflow","slug":"airflow","vulnerabilities":95,"url":"https://junglewise.ai/threats/technologies/airflow"},{"name":"Apache Camel","slug":"camel","vulnerabilities":87,"url":"https://junglewise.ai/threats/technologies/camel"},{"name":"Apache Tomcat","slug":"tomcat","vulnerabilities":87,"url":"https://junglewise.ai/threats/technologies/tomcat"},{"name":"Apache Thrift","slug":"thrift","vulnerabilities":77,"url":"https://junglewise.ai/threats/technologies/thrift"},{"name":"Apache Ofbiz","slug":"ofbiz","vulnerabilities":67,"url":"https://junglewise.ai/threats/technologies/ofbiz"},{"name":"Apache HTTP Server","slug":"http-server","vulnerabilities":62,"url":"https://junglewise.ai/threats/technologies/http-server"},{"name":"Apache Traffic Server","slug":"traffic-server","vulnerabilities":55,"url":"https://junglewise.ai/threats/technologies/traffic-server"},{"name":"Apache Brpc","slug":"brpc","vulnerabilities":36,"url":"https://junglewise.ai/threats/technologies/brpc"},{"name":"Apache Roller","slug":"roller","vulnerabilities":30,"url":"https://junglewise.ai/threats/technologies/roller"},{"name":"Apache CloudStack","slug":"cloudstack","vulnerabilities":28,"url":"https://junglewise.ai/threats/technologies/cloudstack"},{"name":"Apache ActiveMQ","slug":"activemq","vulnerabilities":27,"url":"https://junglewise.ai/threats/technologies/activemq"},{"name":"Apache Apisix","slug":"apisix","vulnerabilities":27,"url":"https://junglewise.ai/threats/technologies/apisix"}],"technology":{"hub":true,"name":"Apache Log4net","slug":"log4net","vendor":{"hub":true,"name":"Apache","slug":"apache","url":"https://junglewise.ai/threats/vendors/apache"},"aliases":[],"category":"library","homepage":"https://logging.apache.org/log4net/","repo_url":"https://github.com/apache/logging-log4net","description":"A tool to help the programmer output log statements to a variety of output targets.","url":"https://junglewise.ai/threats/technologies/log4net"},"most_severe":[{"cve":"CVE-2026-40021","cvss":5.3,"epss":0.0098,"slug":"cve-2026-40021-apache-log4net-log-suppression-in-xmllayout","title":"Apache Log4net log suppression in XmlLayout","severity":"medium","exploited":false,"published_at":"2026-04-10T16:16:32.42+00:00","url":"https://junglewise.ai/threats/cve-2026-40021-apache-log4net-log-suppression-in-xmllayout"},{"cve":"CVE-2026-105244","cvss":5.3,"slug":"cve-2026-105244-improper-encoding-or-escaping-of-output-vulnerability-in-the","title":"Apache log4net improper character escaping in RemoteSyslogAppender","severity":"medium","exploited":false,"published_at":"2026-10-06T20:17:16.297+00:00","url":"https://junglewise.ai/threats/cve-2026-105244-improper-encoding-or-escaping-of-output-vulnerability-in-the"},{"cve":"CVE-2026-105243","cvss":5.3,"slug":"cve-2026-105243-insufficient-logging-vulnerability-in-the-eventlogappender-of","title":"Apache log4net insufficient logging in EventLogAppender","severity":"medium","exploited":false,"published_at":"2026-10-06T20:17:16.167+00:00","url":"https://junglewise.ai/threats/cve-2026-105243-insufficient-logging-vulnerability-in-the-eventlogappender-of"},{"cve":"CVE-2026-105242","cvss":5.3,"slug":"cve-2026-105242-improper-handling-of-exceptional-conditions-vulnerability-in-the","title":"Apache log4net improper handling of exceptions in aspnet-request pattern converter","severity":"medium","exploited":false,"published_at":"2026-10-06T20:17:16.037+00:00","url":"https://junglewise.ai/threats/cve-2026-105242-improper-handling-of-exceptional-conditions-vulnerability-in-the"},{"cve":"CVE-2026-105241","cvss":5.3,"slug":"cve-2026-105241-improper-handling-of-unicode-encoding-vulnerability-in-the","title":"Apache log4net improper Unicode encoding in SmtpPickupDirAppender","severity":"medium","exploited":false,"published_at":"2026-10-06T20:17:15.907+00:00","url":"https://junglewise.ai/threats/cve-2026-105241-improper-handling-of-unicode-encoding-vulnerability-in-the"},{"cve":"CVE-2026-105240","cvss":5.3,"slug":"cve-2026-105240-improper-neutralization-of-null-byte-or-nul-character","title":"Apache log4net null byte handling in OutputDebugStringAppender","severity":"medium","exploited":false,"published_at":"2026-10-06T20:17:15.777+00:00","url":"https://junglewise.ai/threats/cve-2026-105240-improper-neutralization-of-null-byte-or-nul-character"},{"cve":"CVE-2026-105239","cvss":5.3,"slug":"cve-2026-105239-improper-neutralization-of-null-byte-or-nul-character","title":"Apache log4net null byte injection in EventLogAppender","severity":"medium","exploited":false,"published_at":"2026-10-06T20:17:15.63+00:00","url":"https://junglewise.ai/threats/cve-2026-105239-improper-neutralization-of-null-byte-or-nul-character"}],"generated_at":"2026-11-12T03:07:00.164048+00:00"}