CVE-2026-25491 — craftcms/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
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
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 |
Detection & 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
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-25491 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-25491. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-25491 in your dependencies?
O3 Security finds CVE-2026-25491 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.