Vulnerability · Published Jul 23, 2026 · Assigned by VulnCheck

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

Medium 6.1

In plain English

A medium-severity security flaw in DOMPurify from cure53. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 36% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.1Medium
Exploit odds (30 days)0.4%top 64.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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 packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12node-dompurifyno fix listedDEBIAN-CVE-2026-65899
Debian:13node-dompurifyno fix listedDEBIAN-CVE-2026-65899
Debian:14node-dompurify3.4.12+dfsg-1DEBIAN-CVE-2026-65899
Ubuntu:22.04:LTSnode-dompurifyno fix listedUBUNTU-CVE-2026-65899
Ubuntu:24.04:LTSnode-dompurifyno fix listedUBUNTU-CVE-2026-65899
Ubuntu:26.04:LTSnode-dompurifyno fix listedUBUNTU-CVE-2026-65899
npmdompurify3.4.9GHSA-vxr8-fq34-vvx9

Affected products (as reported)

VendorProductVersions
cure53 DOMPurify 0 – before 3.4.9

Weakness: CWE-693 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

References