Medium severity · published Jul 23, 2026
CVE-2026-65903
DOMPurify before 3.4.0 ADD_TAGS Function Bypasses FORBID_TAGS
6.1
CVSS
0.3%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 25% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DO
DOMPurify · cure53
before 3.4.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-65903
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-65903
Exploit
https://github.com/cure53/DOMPurify/security/advisories/GHSA-39q2-94rc-95cp
Third Party Advisory
https://www.vulncheck.com/advisories/dompurify-before-add-tags-function-bypasses-forbid-tags
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