High severity · published Jul 23, 2026
CVE-2026-65898
DOMPurify before 3.4.11 Permanent Attribute Allowlist Pollution via setConfig
7.2
CVSS
0.2%
EPSS
No
On KEV
Description
DOMPurify before 3.4.11 fails to clone the ALLOWED_ATTR allowlist when setConfig() is used with an uponSanitizeAttribute hook, allowing the hook to permanently mutate the shared allowlist. Attackers can register a hook that conditionally allows dangerous attributes like onerror for trusted elements, then submit untrusted content that inherits the polluted allowlist and executes event handlers as stored XSS.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 11% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DO
DOMPurify · cure53
before 3.4.11 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-65898
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-65898
Exploit
https://github.com/cure53/DOMPurify/security/advisories/GHSA-cmwh-pvxp-8882
Third Party Advisory
https://www.vulncheck.com/advisories/dompurify-before-permanent-attribute-allowlist-pollution-via-setconfig
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