Summary
Craft CMS has Stored XSS in Table Field via "HTML" Column Type
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
Impact
Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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See it in your environmentNew to Kodem? Get a demo →Remediation advice
craftcms/cms to 4.16.19 or later; craftcms/cms to 5.8.23 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-27126? CVE-2026-27126 is a medium-severity cross-site scripting (XSS) vulnerability in craftcms/cms (composer), affecting versions >= 4.5.0-RC1, <= 4.16.18. It is fixed in 4.16.19, 5.8.23. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
- Which versions of craftcms/cms are affected by CVE-2026-27126? craftcms/cms (composer) versions >= 4.5.0-RC1, <= 4.16.18 is affected.
- Is there a fix for CVE-2026-27126? Yes. CVE-2026-27126 is fixed in 4.16.19, 5.8.23. Upgrade to this version or later.
- Is CVE-2026-27126 exploitable, and should I be worried? Whether CVE-2026-27126 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-27126 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-27126?
- Upgrade
craftcms/cmsto 4.16.19 or later - Upgrade
craftcms/cmsto 5.8.23 or later
- Upgrade