CVE-2026-65898CWE-79

DOMPurify before 3.4.11 Permanent Attribute Allowlist Pollution via setConfig

Medium · published July 23, 2026

CVSS v4.0
5.1
EPSS
0%
Percentile
21.4
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
5.1 · MEDIUM
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
EPSS
0.00299 · 21.4th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-07-23T13:16Z
EPSS history
Timeline
  • 23 JUL 13:16Z
    DOMPurify before 3.4.11 Permanent Attribute Allowlist Pollution via setConfig
    cvelistv5