{"id":"CVE-2020-26870","aliases":["GHSA-63q7-h895-m982"],"url":"https://o3.security/vulnerability/CVE-2020-26870","summary":"Cross-site Scripting in dompurify","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.","published":"2020-10-07T16:15:18.030Z","modified":"2026-08-07T11:48:28.661427805Z","cvss":{"score":6.1,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"npm","name":"dompurify","fixedVersion":"2.0.17"}],"fix":{"url":"https://github.com/cure53/DOMPurify/commit/02724b8eb048dd219d6725b05c3000936f11d62d","label":"cure53/DOMPurify@02724b8"},"references":[{"type":"ADVISORY","url":"https://lists.debian.org/debian-lts-announce/2020/10/msg00029.html"},{"type":"FIX","url":"https://github.com/cure53/DOMPurify/commit/02724b8eb048dd219d6725b05c3000936f11d62d"},{"type":"FIX","url":"https://github.com/cure53/DOMPurify/compare/2.0.16...2.0.17"},{"type":"FIX","url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-26870"},{"type":"FIX","url":"https://www.oracle.com//security-alerts/cpujul2021.html"},{"type":"EVIDENCE","url":"https://research.securitum.com/mutation-xss-via-mathml-mutation-dompurify-2-0-17-bypass/"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T11:48:28.661427805Z"}}