Vulnerability in Cure53 Dompurify
CVE-2026-65903
DOMPurify before 3.4.0 contains a logic error in the ADD_TAGS function where short-circuit evaluation allows forbidden tags to bypass FORBID_TAGS restrictions. Attackers can craft input containing tags listed in FORBID_TAGS that are also added via ADD_TAGS function, causing them to be retained in sanitized output.
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: 0.003 (24.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 24th percentile — 24.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
- Cure53 Dompurify — versions 0, 3.4.0
Weakness classification (CWE)
References
- github.com/cure53/DOMPurify/security/advisories/GHSA-39q2-94rc-95cp (Exploit, vendor-advisory, Third Party Advisory)
- www.vulncheck.com/advisories/dompurify-before-add-tags-function-bypasses-forbid… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-65903?
- CVE-2026-65903 is a medium-severity vulnerability in Cure53 Dompurify, classified under Incorrect Comparison. CVSS score: 6.1/10. Published 2026-07-23.
- How severe is CVE-2026-65903?
- Medium severity. CVSS v3 base score is 6.1 out of 10.