CVE-2026-24890
📋 TL;DR
OpenEMR patient portal users can forge provider signatures by exploiting an authorization bypass in the signature upload endpoint. This affects all OpenEMR installations prior to version 8.0.0 where patient portal functionality is enabled. Attackers could falsify medical documents, leading to legal and compliance issues.
💻 Affected Systems
- OpenEMR
📦 What is this software?
Openemr by Open Emr
⚠️ Risk & Real-World Impact
Worst Case
Malicious patients forge provider signatures on critical medical documents, leading to fraudulent prescriptions, treatment authorizations, or legal documents with severe legal, financial, and patient safety consequences.
Likely Case
Patients modify or forge signatures on routine medical documents, compromising document integrity and creating compliance violations for healthcare organizations.
If Mitigated
With proper access controls and monitoring, unauthorized signature modifications are prevented or quickly detected, minimizing impact to document authenticity.
🎯 Exploit Status
Exploitation requires authenticated patient portal access but involves simple parameter manipulation (type=admin-signature with arbitrary provider ID).
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 8.0.0
Vendor Advisory: https://github.com/openemr/openemr/security/advisories/GHSA-xc8x-mfh8-9xvh
Restart Required: Yes
Instructions:
1. Backup your OpenEMR installation and database. 2. Download OpenEMR version 8.0.0 or later from the official repository. 3. Follow the OpenEMR upgrade documentation to apply the update. 4. Restart web services and verify functionality.
🔧 Temporary Workarounds
Disable Patient Portal
allTemporarily disable patient portal functionality to prevent exploitation while planning upgrade.
# Edit OpenEMR configuration to disable patient portal
# Location varies by installation - typically in configuration files or admin interface
Restrict Signature Endpoint Access
linuxImplement web application firewall rules or access controls to restrict access to the vulnerable signature upload endpoint.
# Example Apache mod_rewrite rule to block specific endpoint
RewriteRule ^/portal/signature\.php$ - [F]
🧯 If You Can't Patch
- Implement strict monitoring and alerting for signature modification attempts in application logs.
- Add additional authorization checks in the application code to verify user permissions before allowing signature uploads.
🔍 How to Verify
Check if Vulnerable:
Check OpenEMR version via admin interface or by examining source code files. If version is below 8.0.0 and patient portal is enabled, the system is vulnerable.Check Version:
Check OpenEMR version in admin interface or examine version.php file in installation directory.Verify Fix Applied:
After upgrading to 8.0.0 or later, test that authenticated portal users cannot upload signatures with type=admin-signature parameter or modify provider signatures.📡 Detection & Monitoring
Log Indicators:
- Unusual signature upload activity from patient portal users
- Requests to signature endpoint with type=admin-signature parameter
- Multiple failed signature modification attempts
Network Indicators:
- POST requests to /portal/signature.php with admin-signature parameters
- Unusual file upload patterns to signature endpoints
SIEM Query:
source="openemr_logs" AND (uri_path="/portal/signature.php" AND (post_data CONTAINS "type=admin-signature" OR post_data CONTAINS "provider_id="))