CVE-2026-65898

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 4.0

5.1CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

CVSS 3.1

7.2CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

EPSS

0.2% chance of exploitation in the next 30 days; higher than 11% of CVEs (scores of 2026-10-25)

CWE

CWE-79

Published

2026-07-23

Modified

2026-10-24

Record from

the NVD, synced 2026-10-24

Affected

• cure53:dompurify

Packages (OSV)

References

• https://github.com/cure53/DOMPurify/security/advisories/GHSA-cmwh-pvxp-8882
• https://www.vulncheck.com/advisories/dompurify-before-permanent-attribute-allowlist-pollution-via-setconfig
• https://github.com/cure53/DOMPurify/security/advisories/GHSA-cmwh-pvxp-8882

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