{"id":"UBUNTU-CVE-2021-3541","details":"A flaw was found in libxml2. Exponential entity expansion attack its possible bypassing all existing protection mechanisms and leading to denial of service.","modified":"2026-04-22T12:55:32.780721Z","published":"2021-05-18T00:00:00Z","related":["USN-4991-1"],"upstream":["CVE-2021-3541"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-3541"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=1950515"},{"type":"REPORT","url":"https://gitlab.gnome.org/GNOME/libxml2/-/commit/8598060bacada41a0eb09d95c97744ff4e428f8e"},{"type":"REPORT","url":"https://gitlab.gnome.org/GNOME/libxml2/-/issues/228"},{"type":"REPORT","url":"https://blog.hartwork.org/posts/cve-2021-3541-parameter-laughs-fixed-in-libxml2-2-9-11/"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-4991-1"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-3541"}],"affected":[{"package":{"name":"libxml2","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/libxml2@2.9.10+dfsg-5ubuntu0.20.04.1?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.9.10+dfsg-5ubuntu0.20.04.1"}]}],"versions":["2.9.4+dfsg1-7ubuntu3","2.9.4+dfsg1-7ubuntu5","2.9.4+dfsg1-8ubuntu1","2.9.4+dfsg1-8ubuntu2","2.9.4+dfsg1-8ubuntu3","2.9.10+dfsg-1ubuntu3","2.9.10+dfsg-4build1","2.9.10+dfsg-5"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"libxml2","binary_version":"2.9.10+dfsg-5ubuntu0.20.04.1"},{"binary_version":"2.9.10+dfsg-5ubuntu0.20.04.1","binary_name":"libxml2-utils"},{"binary_name":"python-libxml2","binary_version":"2.9.10+dfsg-5ubuntu0.20.04.1"},{"binary_name":"python3-libxml2","binary_version":"2.9.10+dfsg-5ubuntu0.20.04.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-3541.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}