{"id":"DEBIAN-CVE-2026-105243","details":"Insufficient Logging vulnerability in the EventLogAppender of Apache log4net.  Long messages were truncated to a fixed size that exceeds what the Windows Event Log accepts once the log and source names are counted, and the event log then stored nothing and reported nothing. A party whose data reaches a log message could suppress the whole record by making it long enough. Only applications on Windows that use EventLogAppender 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.","modified":"2026-10-08T09:47:33.799189137Z","published":"2026-10-06T20:17:16.167Z","upstream":["CVE-2026-105243"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-105243"}],"affected":[{"package":{"name":"log4net","ecosystem":"Debian:13","purl":"pkg:deb/debian/log4net?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.2.10+dfsg-10","1.2.10+dfsg-9"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-105243.json"}},{"package":{"name":"log4net","ecosystem":"Debian:14","purl":"pkg:deb/debian/log4net?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.2.10+dfsg-10","1.2.10+dfsg-9"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-105243.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"}]}