CVE-2026-65912 — dompurify
CVE-2026-65912 is a Cross-site Scripting (XSS) vulnerability in dompurify. A fix is available for dompurify — see the affected versions and patch details below.
DOMPurify before 3.3.2 URI Validation Bypass via ADD_ATTR
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-2026-65912.
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
DOMPurify allows ADD_ATTR to be provided as a predicate function via EXTRA_ELEMENT_HANDLING.attributeCheck. When the predicate returns true, _isValidAttribute short-circuits the attribute check before URI-safe validation runs. An attacker who supplies a predicate that accepts specific attribute/tag combinations can then sanitize input such as <a href="javascript:alert(document.domain)"> and have the javascript: URL survive, because URI validation is skipped for that attribute while other checks still pass. The provided PoC accepts href for anchors and then triggers a click inside an iframe, showing that the sanitized payload executes despite the protocol bypass.
Impact
Predicate-based allowlisting bypasses DOMPurify's URI validation, allowing unsafe protocols such as javascript: to reach the DOM and execute whenever the link is activated, resulting in DOM-based XSS.
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-2026-65912 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 cross-site scripting (XSS) vulnerability in DOMPurify arises when applications configure ADD_ATTR as a predicate function through EXTRA_ELEMENT_HANDLING.attributeCheck. An attacker could exploit this by crafting malicious input that bypasses URI validation, leading to the execution of unsafe javascript: protocols…
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-2026-65912 (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-2026-65912 in your dependencies?
Find it across npm, including transitive dependencies.