XSS in Cure53 Dompurify
CVE-2026-49458
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.004 (33.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 33.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Cure53 Dompurify — versions < 3.4.6
Weakness classification (CWE)
References
- github.com/cure53/DOMPurify/security/advisories/GHSA-hpcv-96wg-7vj8 (Exploit, Mitigation, Vendor Advisory)
- github.com/cure53/DOMPurify/commit/bb7739e5bccec7e1ab3dae3f3e42d02db3acaaae (Patch)
- github.com/cure53/DOMPurify/releases/tag/3.4.6 (Release Notes)
Frequently asked questions
- What is CVE-2026-49458?
- CVE-2026-49458 is a medium-severity vulnerability in Cure53 Dompurify, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-07-14.
- How severe is CVE-2026-49458?
- Medium severity. CVSS v3 base score is 6.1 out of 10.