What is CVE-2026-65898?

CVE-2026-65898 is a high-severity vulnerability in Cure53 Dompurify, classified under Cross-site Scripting. CVSS score: 7.2/10. Published 2026-07-23.

How severe is CVE-2026-65898?

High severity. CVSS v3 base score is 7.2 out of 10.

XSS in Cure53 Dompurify

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.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.002 (11.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N.

Affected products

Cure53 Dompurify — versions 0, 3.4.11

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

disclosure@vulncheck.com (Exploit, vendor-advisory, Third Party Advisory)
disclosure@vulncheck.com (Third Party Advisory, third-party-advisory)

Frequently asked questions

What is CVE-2026-65898?: CVE-2026-65898 is a high-severity vulnerability in Cure53 Dompurify, classified under Cross-site Scripting. CVSS score: 7.2/10. Published 2026-07-23.
How severe is CVE-2026-65898?: High severity. CVSS v3 base score is 7.2 out of 10.