๐Ÿ” CVE Alert

CVE-2026-65902

MEDIUM 6.1

DOMPurify before 3.4.7 Hook Mutation Pollution via allowedTags

CVSS Score
6.1
EPSS Score
0.0%
EPSS Percentile
0th

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.

CWE CWE-501
Vendor cure53
Product dompurify
Published Jul 23, 2026
Last Updated Jul 23, 2026
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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

Affected Versions

cure53 / DOMPurify
0 < 3.4.7

References

NVD โ†— CVE.org โ†— EPSS Data โ†—
github.com: https://github.com/cure53/DOMPurify/security/advisories/GHSA-76mc-f452-cxcm github.com: https://github.com/cure53/DOMPurify/commit/7996f1dc78eb8b7922388aed75d94a9f8fad9a36 vulncheck.com: https://www.vulncheck.com/advisories/dompurify-before-hook-mutation-pollution-via-allowedtags

Credits

๐Ÿ” offset