Vulnerability Description
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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Cure53 | Dompurify | < 3.4.0 |
Related Weaknesses (CWE)
References
- https://github.com/cure53/DOMPurify/security/advisories/GHSA-39q2-94rc-95cpExploitThird Party Advisory
- https://www.vulncheck.com/advisories/dompurify-before-add-tags-function-bypassesThird Party Advisory
FAQ
What is CVE-2026-65903?
CVE-2026-65903 is a vulnerability with a CVSS score of 6.1 (MEDIUM). 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 tag...
How severe is CVE-2026-65903?
CVE-2026-65903 has been rated MEDIUM with a CVSS base score of 6.1/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-65903?
Check the references section above for vendor advisories and patch information. Affected products include: Cure53 Dompurify.