{"id":"UBUNTU-CVE-2020-26870","details":"Cure53 DOMPurify before 2.0.17 allows mutation XSS. This occurs because a serialize-parse roundtrip does not necessarily return the original DOM tree, and a namespace can change from HTML to MathML, as demonstrated by nesting of FORM elements.","modified":"2025-10-24T04:48:49Z","published":"2020-10-07T16:15:00Z","upstream":["CVE-2020-26870"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2020-26870"},{"type":"REPORT","url":"https://research.securitum.com/mutation-xss-via-mathml-mutation-dompurify-2-0-17-bypass/"},{"type":"REPORT","url":"https://github.com/cure53/DOMPurify/commit/02724b8eb048dd219d6725b05c3000936f11d62d"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2020-26870"}],"affected":[{"package":{"name":"dompurify.js","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/dompurify.js@0.7.3~dfsg1-2?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.7.3~dfsg1-1","0.7.3~dfsg1-2"],"ecosystem_specific":{"binaries":[{"binary_name":"libjs-dompurify","binary_version":"0.7.3~dfsg1-2"},{"binary_name":"node-dompurify","binary_version":"0.7.3~dfsg1-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-26870.json"}},{"package":{"name":"dompurify.js","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/dompurify.js@0.9.0~dfsg1-2?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.9.0~dfsg1-1","0.9.0~dfsg1-2"],"ecosystem_specific":{"binaries":[{"binary_name":"libjs-dompurify","binary_version":"0.9.0~dfsg1-2"},{"binary_name":"node-dompurify","binary_version":"0.9.0~dfsg1-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-26870.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},{"type":"Ubuntu","score":"low"}]}