CVE-2026-25491 — cms
Fix: craftcms/cms@cfd6ba0CVE-2026-25491 is a Cross-site Scripting (XSS) vulnerability in craftcms/cms. A fix is available for craftcms/cms — see the affected versions and patch details below.
Craft has a Stored XSS in Entry Types Name
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-2026-25491.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
Real-World Exposure
craftcms/cmsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Summary
Stored XSS via Entry Type names. The name is not sanitized when displayed in the Entry Types list.
Proof of Concept
Required Permissions (Attacker)
- Admin access (only admins have access to the settings page)
allowAdminChangesis enabled in production, which is against our security recommendations.
Steps to Reproduce
- Log in as an attacker.
- Go to Settings -> Entry Types (
/admin/settings/entry-types). - Create a new Entry Type.
- Set Name to:
<img src=x onerror="alert('XSS-EntryTypes')" hidden>
- Save the Entry Type, and you’ll be redirected back to the entry types table automatically.
- Notice the alert fires when the entry types table renders.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | craftcms/cms | ≥ 5.0.0-RC1&&< 5.8.22 | 5.8.22composer require craftcms/cms:^5.8.22 |
Affected Products
craft cmscraftcmsDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for craftcms/cms, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update craftcms/cms to 5.8.22 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-25491 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.
Frequently Asked Questions
Is CVE-2026-25491 in your dependencies?
Find it across Packagist, including transitive dependencies.