{"id":"UBUNTU-CVE-2026-66010","details":"DOMPurify before 3.4.12 fails to execute afterSanitizeElements hook for custom elements allowed via CUSTOM_ELEMENT_HANDLING.tagNameCheck, allowing attributes to bypass application security policies. Attackers can preserve sensitive attributes on custom elements that later re-inject them into innerHTML sinks, creating second-order XSS gadgets.","modified":"2026-07-29T08:01:44Z","published":"2026-07-24T13:18:00Z","upstream":["CVE-2026-66010"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-66010"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-66010"},{"type":"REPORT","url":"https://github.com/cure53/DOMPurify/security/advisories/GHSA-c2j3-45gr-mqc4"},{"type":"REPORT","url":"https://www.vulncheck.com/advisories/dompurify-before-hook-bypass-via-custom-element-handling"}],"affected":[{"package":{"name":"node-dompurify","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/node-dompurify?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.3.0+dfsg-2","2.3.3+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_name":"node-dompurify","binary_version":"2.3.3+dfsg-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-66010.json"}},{"package":{"name":"node-dompurify","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/node-dompurify?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.4.1+dfsg+~2.4.0-1","3.0.9+dfsg+~3.0.5-1"],"ecosystem_specific":{"binaries":[{"binary_name":"node-dompurify","binary_version":"3.0.9+dfsg+~3.0.5-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-66010.json"}},{"package":{"name":"node-dompurify","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/node-dompurify?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.1.7+dfsg+~3.0.5-2","3.3.3+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_name":"node-dompurify","binary_version":"3.3.3+dfsg-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-66010.json"}}],"schema_version":"1.7.5","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":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N"},{"type":"Ubuntu","score":"medium"}]}