CVE-2026-65913 — dompurify
CVE-2026-65913 is a CWE-1321 vulnerability in dompurify. A fix is available for dompurify — see the affected versions and patch details below.
DOMPurify before 3.3.2 Prototype Pollution via USE_PROFILES
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-65913.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
dompurifynpmDescription
Summary
When USE_PROFILES is enabled, DOMPurify rebuilds ALLOWED_ATTR as a plain array before populating it with the requested allowlists. Because the sanitizer still looks up attributes via ALLOWED_ATTR[lcName], any Array.prototype property that is polluted also counts as an allowlisted attribute. An attacker who can set Array.prototype.onclick = true (or a runtime already subject to prototype pollution) can thus force DOMPurify to keep event handlers such as onclick even when they are normally forbidden. The provided PoC sanitizes <img onclick=...> with USE_PROFILES and adds the sanitized output to the DOM; the polluted prototype allows the event handler to survive and execute, turning what should be a blocklist into a silent XSS vector.
Impact
Prototype pollution makes DOMPurify accept dangerous event handler attributes, which bypasses the sanitizer and results in DOM-based XSS once the sanitized markup is rendered.
Credits
Identified by Cantina’s Apex (https://www.cantina.security).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | dompurify | all versions | 3.3.2npm install dompurify@3.3.2 |
Affected Products
dompurifycure53Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for dompurify, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update dompurify to 3.3.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-65913 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This flaw in DOMPurify allows for Cross-Site Scripting (XSS) when the library is configured to use `USE_PROFILES` mode. An attacker could exploit a prototype pollution vulnerability to bypass attribute filtering, enabling the execution of arbitrary JavaScript within the user's browser upon rendering of sanitized…
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.Source: Red Hat security advisory for CVE-2026-65913 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Hardened Images | grafana13-1-main-13.1.3-0.1.1.hum1 | RHSA-2026:54517 |
| Red Hat Hardened Images | grafana12-4-main-12.4.8-0.1.2.hum1 | RHSA-2026:58500 |
Frequently Asked Questions
Is CVE-2026-65913 in your dependencies?
Find it across npm, including transitive dependencies.