CVE-2026-65899

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.

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