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

mediumCVSS 6.1CVE-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.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: medium — CVSS 6.1
Published: 2026-07-23
Last updated: 2026-07-28
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-65899

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-658990.23% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 14% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-65899	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

lowGHSA-vxr8-fq34-vvx9: DOMPurify: Trusted Types policy survives `clearConfig()` and can poison later `RETURN_TRU…ghsa

Recent advisories for DOMPurify

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

high[NEW] [high] Red Hat Ansible Automation Platform (node-tar, linkify-it, protobufjs, brace-expansion, fast-uri,…cert-bund · 2026-08-04
mediumCVE-2026-66010: DOMPurify before 3.4.12 fails to execute afterSanitizeElements hook for custom elements allowe…nvd · 2026-07-24
mediumCVE-2026-65914: DOMPurify before 3.3.2 contains a mutation-XSS vulnerability when sanitized HTML is reinserted…nvd · 2026-07-23
mediumCVE-2026-65913: DOMPurify before 3.3.2 contains a prototype pollution vulnerability in USE_PROFILES mode that …nvd · 2026-07-23
mediumCVE-2026-65912: DOMPurify before 3.3.2 contains a URI validation bypass vulnerability when ADD_ATTR is provide…nvd · 2026-07-23
mediumCVE-2026-65911: In DOMPurify through 3.3.3, function predicates supplied via ADD_ATTR or ADD_TAGS to DOMPurify…nvd · 2026-07-23