Vulnerability in Cure53 Dompurify
CVE-2026-65902
DOMPurify before 3.4.7 (affected versions <= 3.4.5) passes direct references to the module-level DEFAULT_ALLOWED_TAGS and DEFAULT_ALLOWED_ATTR sets to the uponSanitizeElement and uponSanitizeAttribute hooks via data.allowedTags / data.allowedAttributes when sanitize is called without an explicit cfg.ALLOWED_TAGS / cfg.ALLOWED_ATTR array. A hook that mutates these fields permanently widens the default allow-lists for the lifetime of the DOMPurify instance, so all subsequent default-config sanitize calls inherit the widened defaults and attacker payloads using the poisoned tag/attribute name survive sanitization. removeAllHooks(), clearConfig(), and passing a fresh cfg do not recover the state; only constructing a new DOMPurify instance does.
EPSS: 0.002 (14.7th percentile) — read the EPSS interpretation.
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.
Affected products
- Cure53 Dompurify — versions 0, 3.4.7
Weakness classification (CWE)
References
- disclosure@vulncheck.com (Exploit, vendor-advisory, Third Party Advisory)
- disclosure@vulncheck.com (Patch, patch)
- disclosure@vulncheck.com (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-65902?
- CVE-2026-65902 is a medium-severity vulnerability in Cure53 Dompurify, classified under Trust Boundary Violation. CVSS score: 6.1/10. Published 2026-07-23.
- How severe is CVE-2026-65902?
- Medium severity. CVSS v3 base score is 6.1 out of 10.