CVE-2026-65898
DOMPurify before 3.4.11 Permanent Attribute Allowlist Pollution via setConfig
MEDIUM 5.1EPSS 0.3%
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.
- Affected
- cure53 · DOMPurify
- CVSS v4.0 VULNCHECK
- 5.1 MEDIUM
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS v4.0 GitHub
- 5.1 MEDIUM
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 - CVSS v3.1 VULNCHECK
- 7.2 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N - EPSS
- 0.30% chance of exploitation in the next 30 days, 21st percentile
- Published
- 2026-07-23
Proof-of-concept exploits (1)
Security advisories
- cure53/DOMPurify/security/advisories/GHSA-cmwh-pvxp-8882
- https://www.vulncheck.com/advisories/dompurify-before-permanent-attribute-allowlist-pollu…