{"id":"UBUNTU-CVE-2026-20031","details":"A vulnerability in the HTML Cascading Style Sheets (CSS) module of ClamAV could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper error handling when splitting UTF-8 strings. An attacker could exploit this vulnerability by submitting a crafted HTML file to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to terminate the scanning process.","modified":"2026-04-22T20:16:23.972517Z","published":"2026-03-04T18:16:00Z","upstream":["CVE-2026-20031"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-20031"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-20031"},{"type":"REPORT","url":"https://blog.clamav.net/2026/03/clamav-152-and-144-security-patch.html"}],"affected":[{"package":{"name":"clamav","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/clamav@0.103.9+dfsg-0ubuntu0.14.04.1+esm1?arch=source&distro=esm-infra-legacy/trusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.97.8+dfsg-1ubuntu4","0.97.8+dfsg-1ubuntu5","0.98.1+dfsg-1ubuntu4","0.98.1+dfsg-1ubuntu5","0.98.1+dfsg-2ubuntu2","0.98.1+dfsg-4ubuntu1","0.98.1+dfsg-4ubuntu1.1","0.98.5+addedllvm-0ubuntu0.14.04.1","0.98.6+dfsg-0ubuntu0.14.04.1","0.98.7+dfsg-0ubuntu0.14.04.1","0.99.2+addedllvm-0ubuntu0.14.04.1","0.99.2+addedllvm-0ubuntu0.14.04.2","0.99.3+addedllvm-0ubuntu0.14.04.1","0.99.4+addedllvm-0ubuntu0.14.04.1","0.100.1+dfsg-1ubuntu0.14.04.1","0.100.1+dfsg-1ubuntu0.14.04.2","0.100.1+dfsg-1ubuntu0.14.04.3","0.100.1+dfsg-1ubuntu0.14.04.4","0.100.2+dfsg-1ubuntu0.14.04.1","0.100.2+dfsg-1ubuntu0.14.04.2","0.100.3+dfsg-0ubuntu0.14.04.1","0.100.3+dfsg-0ubuntu0.14.04.1+esm1","0.101.4+dfsg-0ubuntu0.14.04.1+esm1","0.102.1+dfsg-0ubuntu0.14.04.1+esm1","0.102.2+dfsg-0ubuntu0.14.04.1+esm1","0.102.3+dfsg-0ubuntu0.14.04.1+esm1","0.102.4+dfsg-0ubuntu0.14.04.1+esm1","0.103.2+dfsg-0ubuntu0.14.04.1+esm1","0.103.2+dfsg-0ubuntu0.14.04.1+esm2","0.103.5+dfsg-0ubuntu0.14.04.1+esm1","0.103.6+dfsg-0ubuntu0.14.04.1+esm1","0.103.8+dfsg-0ubuntu0.14.04.1+esm1","0.103.9+dfsg-0ubuntu0.14.04.1+esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"clamav","binary_version":"0.103.9+dfsg-0ubuntu0.14.04.1+esm1"},{"binary_name":"clamav-base","binary_version":"0.103.9+dfsg-0ubuntu0.14.04.1+esm1"},{"binary_name":"clamav-daemon","binary_version":"0.103.9+dfsg-0ubuntu0.14.04.1+esm1"},{"binary_name":"clamav-docs","binary_version":"0.103.9+dfsg-0ubuntu0.14.04.1+esm1"},{"binary_name":"clamav-freshclam","binary_version":"0.103.9+dfsg-0ubuntu0.14.04.1+esm1"},{"binary_name":"clamav-milter","binary_version":"0.103.9+dfsg-0ubuntu0.14.04.1+esm1"},{"binary_name":"clamav-testfiles","binary_version":"0.103.9+dfsg-0ubuntu0.14.04.1+esm1"},{"binary_name":"libclamav9","binary_version":"0.103.9+dfsg-0ubuntu0.14.04.1+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-20031.json"}},{"package":{"name":"clamav","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/clamav@0.103.12+dfsg-0ubuntu0.16.04.1+esm1?arch=source&distro=esm-infra/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.98.7+dfsg-0ubuntu4","0.98.7+dfsg-0ubuntu5","0.99+dfsg-1ubuntu1","0.99+dfsg-1ubuntu1.1","0.99+dfsg-1ubuntu1.2","0.99.2+dfsg-0ubuntu0.16.04.1","0.99.2+dfsg-0ubuntu0.16.04.2","0.99.2+dfsg-0ubuntu0.16.04.3","0.99.3+addedllvm-0ubuntu0.16.04.1","0.99.4+addedllvm-0ubuntu0.16.04.1","0.100.1+dfsg-1ubuntu0.16.04.1","0.100.1+dfsg-1ubuntu0.16.04.2","0.100.1+dfsg-1ubuntu0.16.04.3","0.100.2+dfsg-1ubuntu0.16.04.1","0.100.3+dfsg-0ubuntu0.16.04.1","0.101.4+dfsg-0ubuntu0.16.04.1","0.102.1+dfsg-0ubuntu0.16.04.2","0.102.2+dfsg-0ubuntu0.16.04.1","0.102.3+dfsg-0ubuntu0.16.04.1","0.102.4+dfsg-0ubuntu0.16.04.1","0.103.2+dfsg-0ubuntu0.16.04.1","0.103.2+dfsg-0ubuntu0.16.04.1+esm1","0.103.5+dfsg-0ubuntu0.16.04.1+esm1","0.103.6+dfsg-0ubuntu0.16.04.1+esm1","0.103.8+dfsg-0ubuntu0.16.04.1+esm1","0.103.9+dfsg-0ubuntu0.16.04.1+esm1","0.103.12+dfsg-0ubuntu0.16.04.1+esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"clamav","binary_version":"0.103.12+dfsg-0ubuntu0.16.04.1+esm1"},{"binary_name":"clamav-base","binary_version":"0.103.12+dfsg-0ubuntu0.16.04.1+esm1"},{"binary_name":"clamav-daemon","binary_version":"0.103.12+dfsg-0ubuntu0.16.04.1+esm1"},{"binary_name":"clamav-docs","binary_version":"0.103.12+dfsg-0ubuntu0.16.04.1+esm1"},{"binary_name":"clamav-freshclam","binary_version":"0.103.12+dfsg-0ubuntu0.16.04.1+esm1"},{"binary_name":"clamav-milter","binary_version":"0.103.12+dfsg-0ubuntu0.16.04.1+esm1"},{"binary_name":"clamav-testfiles","binary_version":"0.103.12+dfsg-0ubuntu0.16.04.1+esm1"},{"binary_name":"clamdscan","binary_version":"0.103.12+dfsg-0ubuntu0.16.04.1+esm1"},{"binary_name":"libclamav9","binary_version":"0.103.12+dfsg-0ubuntu0.16.04.1+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-20031.json"}},{"package":{"name":"clamav","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/clamav@0.103.12+dfsg-0ubuntu0.18.04.1+esm1?arch=source&distro=esm-infra/bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.99.2+dfsg-6ubuntu2","0.99.3~beta1+dfsg-2ubuntu1","0.99.3~beta1+dfsg-2ubuntu2","0.99.3+addedllvm-0ubuntu1","0.99.3+addedllvm-0ubuntu2","0.99.4+addedllvm-0ubuntu1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