{"id":"CVE-2026-66010","revision":"0a2c06a819124306b0c5e89e85719915","records":[{"revision":"0a2c06a819124306b0c5e89e85719915","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-66010","aliases":[],"title":"DOMPurify before 3.4.12 Hook Bypass via CUSTOM_ELEMENT_HANDLING","description":"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.","state":0,"publishedAt":"2026-07-24T12:07:57.374+00:00","modifiedAt":"2026-09-17T17:54:37.884+00:00","affected":[{"ecosystem":"Vendor product","name":"DOMPurify","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"cure53\",\n                    \"product\": \"DOMPurify\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"packageURL\": \"pkg:npm/dompurify\",\n                    \"versions\": [\n                        {\n                            \"version\": \"0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\",\n                            \"lessThan\": \"3.4.12\"\n                        },\n                        {\n                            \"version\": \"3.4.12\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"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","score":5.1,"severity":"MEDIUM"},{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","score":6.1,"severity":"MEDIUM"}],"references":["https://github.com/cure53/DOMPurify/security/advisories/GHSA-c2j3-45gr-mqc4","https://www.vulncheck.com/advisories/dompurify-before-hook-bypass-via-custom-element-handling"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-66010","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-66010","identifiers":["CVE-2026-66010"]},"retained":false,"historicalAffected":[]}],"coverage":[]}