medium6.1
CVE-2026-49458
DOMPurify: Cross-realm IN_PLACE sanitization leaves executable markup intact via realm-bound `instanceof` checks
Impact
DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.6, DOMPurify.sanitize(node, { IN_PLACE: true }) accepted same-origin foreign-realm DOM nodes while follow-on checks used parent-realm constructors, causing instanceof checks for forms, named node maps, document fragments, and elements to fail and skip clobber, template-content, and shadow-DOM sanitization branches so executable markup could survive. This issue is fixed in version 3.4.6.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | dompurify | <= 3.4.5 | 3.4.6 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Cure53 | Dompurify | before 3.4.6 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-hpcv-96wg-7vj8
- https://github.com/cure53/DOMPurify/security/advisories/GHSA-hpcv-96wg-7vj8
- https://github.com/cure53/DOMPurify/commit/bb7739e5bccec7e1ab3dae3f3e42d02db3acaaae
- https://github.com/cure53/DOMPurify/releases/tag/3.4.6