Craft CMS has Stored XSS in Table Field in its "Row Heading" Column Type

A stored Cross-site Scripting (XSS) vulnerability exists in the editableTable.twig component when using the Row Heading column type. The application fails to sanitize input within row headings, allowing an attacker to execute arbitrary JavaScript when another user views a page with the malicious table field.

Prerequisites

• An administrator account
• allowAdminChanges must be enabled in production, which is against security recommendations.

Steps to Reproduce

1. Navigate to Settings → Fields and create a new field with Type: Table
2. Add a Column Heading and set Column Type to Row Heading
3. In Default Values section, add a row with the following payload:

   <img src=x onerror="alert('XSS')">
   

4. Enable Static Rows
5. Use the field in any object (e.g., user profile fields) → then visit any user’s profile
6. Notice the XSS execution

Resources

https://github.com/craftcms/cms/commit/7b372de262b8d9d2ce859f32780c3715719b6f5a