medium6.1
CVE-2026-66010
DOMPurify before 3.4.12 fails to execute afterSanitizeElements hook for custom elements allowed via CUSTOM_ELEMENT_HANDLING.tagNameCheck, allowing attributes t…
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | dompurify | <= 3.4.11 | 3.4.12 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Cure53 | Dompurify | before 3.4.12 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-c2j3-45gr-mqc4
- https://github.com/cure53/DOMPurify/security/advisories/GHSA-c2j3-45gr-mqc4
- https://github.com/cure53/DOMPurify/pull/1537
- https://github.com/cure53/DOMPurify/commit/a9ca1e537422319a557a9a2aa61f003b23b4a197
- https://github.com/cure53/DOMPurify/releases/tag/3.4.12
- https://nvd.nist.gov/vuln/detail/CVE-2026-66010
- https://www.vulncheck.com/advisories/dompurify-before-hook-bypass-via-custom-element-handling