CVE-2026-22241
📋 TL;DR
CVE-2026-22241 is an arbitrary file upload vulnerability in Open eClass (formerly GUnet eClass) that allows authenticated administrators to upload malicious files via the theme import functionality. This leads to remote code execution on the web server. Organizations running Open eClass versions prior to 4.2 are affected.
💻 Affected Systems
- Open eClass (formerly GUnet eClass)
📦 What is this software?
Openeclass by Openeclass
⚠️ Risk & Real-World Impact
Worst Case
Full server compromise allowing attacker to execute arbitrary code, access sensitive data, pivot to internal networks, and maintain persistent access.
Likely Case
Web server compromise leading to data theft, defacement, or deployment of malware/backdoors on the affected system.
If Mitigated
Limited impact if proper file validation and privilege separation are implemented, though administrative access could still lead to other attacks.
🎯 Exploit Status
Exploitation requires administrative access. Public technical details and proof-of-concept are available in security advisories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 4.2
Vendor Advisory: https://github.com/gunet/openeclass/security/advisories/GHSA-gq72-7mwg-424r
Restart Required: Yes
Instructions:
1. Backup your Open eClass installation and database. 2. Download Open eClass version 4.2 from the official repository. 3. Follow the upgrade instructions in the documentation. 4. Restart the web server service. 5. Verify the patch is applied by checking the version.
🔧 Temporary Workarounds
Disable theme import functionality
allTemporarily disable or restrict access to the theme import feature until patching can be completed.
# Modify application configuration or use web server rules to block access to theme import endpoints
Implement file upload restrictions
linuxConfigure web server to reject zip file uploads or implement additional validation at the web server level.
# Example for Apache: SetEnvIf Request_URI "\.zip$" block_upload
# Example for Nginx: location ~ \.zip$ { deny all; }
🧯 If You Can't Patch
- Implement strict access controls and monitoring for administrative accounts
- Deploy web application firewall (WAF) rules to detect and block malicious file uploads
🔍 How to Verify
Check if Vulnerable:
Check if Open eClass version is below 4.2 and if administrative users can upload zip files via theme import.Check Version:
Check the version in the Open eClass admin panel or review the application files for version information.Verify Fix Applied:
Verify the installed version is 4.2 or higher and test that zip file uploads are properly validated.📡 Detection & Monitoring
Log Indicators:
- Unusual file uploads via theme import functionality
- Administrative user uploading zip files
- Execution of unexpected files in web directories
Network Indicators:
- POST requests to theme import endpoints with zip file uploads
- Unusual outbound connections from the web server
SIEM Query:
source="web_server" AND (uri="*theme*import*" OR uri="*upload*") AND file_extension="zip"🔗 References
- https://github.com/gunet/openeclass/commit/3f9d267b79812a4dd708bb1302339e6a5abe67d9
- https://github.com/gunet/openeclass/security/advisories/GHSA-gq72-7mwg-424r
- https://github.com/gunet/openeclass/security/advisories/GHSA-rf6j-xgqp-wjxg
- https://github.com/gunet/openeclass/security/advisories/GHSA-gq72-7mwg-424r
- https://twelvesec.com/2026/01/16/rce-via-arbitrary-file-upload-at-open-eclass/
- https://github.com/gunet/openeclass/security/advisories/GHSA-rf6j-xgqp-wjxg
