CVE-2025-40834
📋 TL;DR
A cross-site scripting (XSS) vulnerability exists in Mendix RichText widget versions 4.0.0 through 4.6.0 due to improper input sanitization. This allows attackers to inject malicious scripts that execute in users' browsers when they interact with affected RichText content. Organizations using Mendix applications with the vulnerable RichText widget are affected.
💻 Affected Systems
- Mendix RichText widget
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal user session cookies, credentials, or sensitive data, perform actions on behalf of authenticated users, deface applications, or redirect users to malicious sites.
Likely Case
Attackers inject malicious scripts that steal session tokens or user data when victims interact with crafted RichText content, potentially leading to account compromise.
If Mitigated
With proper input validation and output encoding controls, the risk is limited to potential data leakage from unsanitized content display.
🎯 Exploit Status
Exploitation requires the attacker to inject malicious content into the RichText widget, which typically requires some level of application access or user interaction.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: V4.6.1
Vendor Advisory: https://cert-portal.siemens.com/productcert/html/ssa-190588.html
Restart Required: Yes
Instructions:
1. Update Mendix RichText widget to version 4.6.1 or later. 2. Redeploy affected Mendix applications. 3. Test application functionality after update.
🔧 Temporary Workarounds
Input validation and output encoding
allImplement server-side input validation and proper output encoding for all RichText widget content
Content Security Policy
allImplement strict Content Security Policy headers to restrict script execution
🧯 If You Can't Patch
- Implement web application firewall rules to block XSS payloads
- Disable or restrict RichText widget functionality in affected applications
🔍 How to Verify
Check if Vulnerable:
Check Mendix application dependencies for RichText widget version 4.0.0 through 4.6.0Check Version:
Check Mendix project's mxproject.json or package.json for RichText widget versionVerify Fix Applied:
Verify RichText widget version is 4.6.1 or higher in application dependencies📡 Detection & Monitoring
Log Indicators:
- Unusual script tags or JavaScript in RichText content submissions
- Multiple failed input validation attempts
Network Indicators:
- HTTP requests containing suspicious script payloads to RichText endpoints
SIEM Query:
source="web_logs" AND (uri="*/richtext*" OR uri="*/api/richtext*") AND (content CONTAINS "<script>" OR content CONTAINS "javascript:")