{"id":"CVE-2026-66010","summary":"DOMPurify before 3.4.12 Hook Bypass via CUSTOM_ELEMENT_HANDLING","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.","aliases":["GHSA-c2j3-45gr-mqc4"],"modified":"2026-08-12T03:51:08.903946641Z","published":"2026-07-24T12:07:57.374Z","database_specific":{"cwe_ids":["CWE-79"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66010.json","cna_assigner":"VulnCheck"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66010.json"},{"type":"ADVISORY","url":"https://github.com/cure53/DOMPurify/security/advisories/GHSA-c2j3-45gr-mqc4"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-66010"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/dompurify-before-hook-bypass-via-custom-element-handling"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/cure53/dompurify","events":[{"introduced":"0"},{"fixed":"a9ca1e537422319a557a9a2aa61f003b23b4a197"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"3.4.12"}],"source":["AFFECTED_FIELD","CPE_RANGE"],"cpe":"cpe:2.3:a:cure53:dompurify:*:*:*:*:*:*:*:*"}}],"versions":["3.4.11","3.4.10","3.4.9","3.4.8","3.4.7","3.4.6","3.4.5","3.4.4","3.4.3","3.4.2","3.4.1","3.4.0","3.3.3","3.2.3","3.1.3","3.0.4","2.4.3","2.4.2","2.4.1","2.4.0","2.3.12","2.3.11","2.3.10","2.3.9","2.3.8","2.3.6","2.3.5","2.3.4","2.3.3","2.3.2","2.3.1","2.3.0","2.2.9","2.2.8","2.2.7","2.2.6","2.2.4","2.2.3","2.2.2","2.2.0","2.1.1","2.1.0","2.0.17","2.0.16","2.0.15","2.0.14","2.0.13","2.0.12","2.0.11","2.0.10","2.0.9","2.0.8","2.0.6","2.0.5","2.0.4","2.0.3","2.0.2","2.0.1","2.0.0","1.0.11","1.0.10","1.0.9","1.0.8","1.0.7","1.0.6","1.0.5","1.0.4","1.0.3","1.0.2","1.0.1","1.0.0","0.9.0","0.8.9","0.8.8","0.8.7","0.8.6","0.8.5","0.8.4","0.8.3","0.8.2","0.8.1","0.8.0","0.7.3","0.7.2","0.7.1","0.7.0","0.6.7","0.6.6","0.6.5","0.6.4","0.6.3","0.6.2","0.6.1","0.6.0","0.4.5","0.4.4","0.4.3","0.4.2","0.4","0.3","v0.3","0.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-66010.json"}}],"schema_version":"1.9.0","severity":[{"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"}]}