What’s Vulnerable › Vulnerabilities

CVE-2026-65899: DOMPurify before 3.4.9 Trusted Types Policy State Contamination

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-07-23 · updated 2026-10-24
• Weakness: CWE-693

Description

DOMPurify 3.0.0 before 3.4.9 does not reset the retained Trusted Types policy when clearConfig() is called, so a DOMPurify instance reused across trust boundaries stays bound to a previously supplied TRUSTED_TYPES_POLICY. A later caller that requests RETURN_TRUSTED_TYPE output receives a TrustedHTML object created by the old (potentially unsafe) policy rather than a clean default, which can lead to script execution at a Trusted Types sink. Passing TRUSTED_TYPES_POLICY: null on the later call also does not clear the retained policy.

Affected products

• cure53 DOMPurify: from 3.0.0 before 3.4.9 — fixed in 3.4.9

How to fix

Upgrade to a fixed version: cure53 DOMPurify 3.4.9. Check the vendor advisory for mitigations.

References

• https://github.com/cure53/DOMPurify/commit/825e617753ac1169306a542d3174a77f717a0cf6
• https://github.com/cure53/DOMPurify/security/advisories/GHSA-vxr8-fq34-vvx9
• https://www.vulncheck.com/advisories/dompurify-before-trusted-types-policy-state-contamination

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