CVE-2026-27126 — cms
Fix: craftcms/cms@f5d488dCVE-2026-27126 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 CMS has Stored XSS in Table Field via "HTML" Column Type
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-27126.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
Real-World Exposure
craftcms/cms🐘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
A stored Cross-site Scripting (XSS) vulnerability exists in the editableTable.twig component when using the html column type. The application fails to sanitize the input, allowing an attacker to execute arbitrary JavaScript when another user views a page with the malicious table field.
Prerequisites
- An administrator account
allowAdminChangesmust be enabled in production, which is against our security recommendations.
Steps to Reproduce
- Navigate to Settings → Fields and create a new field with Type: Table
- Add a Column Heading and set Column Type to
Single-line text- Note: The vulnerable Column Type is
html, but it's not available in the UI dropdown.
- Note: The vulnerable Column Type is
- In Default Values section, add a row with the following payload:
<img src=x onerror="alert('XSS')"> - Enable
Static Rows - Intercept the Save Field request using a proxy tool (e.g., Burp Suite) or use
cURLdirectly - Modify the request body and change the
types[craft-fields-Table][columns][col3][type]parameter fromsinglelinetohtml - Forward the request to save the field
- Use the field in any object (e.g. user profile fields) → then visit the any user's profile
- Notice the XSS execution
- The XSS will also trigger when an administrator attempts to edit this field, as the malicious payload is executed within the field configuration page, too.
Resources
https://github.com/craftcms/cms/commit/f5d488d9bb6eff7670ed2c2fe30e15692e92c52b
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | craftcms/cms | ≥ 4.5.0-RC1&&< 4.16.19 | 4.16.19composer require craftcms/cms:^4.16.19 |
| 🐘Packagist | craftcms/cms | ≥ 5.0.0-RC1&&< 5.8.23 | 5.8.23composer require craftcms/cms:^5.8.23 |
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 4.16.19 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-27126 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-2026-27126 in your dependencies?
Find it across Packagist, including transitive dependencies.