CVE-2026-26045
📋 TL;DR
This vulnerability in Moodle's backup restore functionality allows authenticated privileged users to upload specially crafted backup files that bypass validation, potentially leading to server-side code execution. It affects Moodle installations where backup restore capabilities are enabled. Successful exploitation could result in full compromise of the Moodle server.
💻 Affected Systems
- Moodle
📦 What is this software?
Moodle by Moodle
Moodle by Moodle
Moodle by Moodle
⚠️ Risk & Real-World Impact
Worst Case
Full compromise of the Moodle server with complete administrative control, data theft, and potential lateral movement to other systems.
Likely Case
Unauthorized code execution leading to data manipulation, privilege escalation, or installation of persistent backdoors.
If Mitigated
Limited impact if proper access controls restrict backup restore to trusted administrators only.
🎯 Exploit Status
Exploitation requires authenticated access with backup restore privileges and ability to upload malicious backup files.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Moodle security advisories for specific patched versions
Vendor Advisory: https://moodle.org/security/
Restart Required: No
Instructions:
1. Check Moodle security advisory for CVE-2026-26045. 2. Update to the patched version. 3. Verify backup restore functionality still works correctly.
🔧 Temporary Workarounds
Restrict Backup Restore Access
allLimit backup restore capabilities to only essential, trusted administrators.
Configure Moodle role permissions to remove backup/restore capabilities from non-essential users
Disable Backup Restore
allTemporarily disable backup restore functionality if not required.
Set Moodle configuration to disable backup/restore features
🧯 If You Can't Patch
- Implement strict access controls to limit backup restore to minimal trusted personnel
- Monitor backup restore activities and audit logs for suspicious file uploads
🔍 How to Verify
Check if Vulnerable:
Check Moodle version against security advisory for CVE-2026-26045Check Version:
Check Moodle admin panel or version.php file for current versionVerify Fix Applied:
Verify Moodle version is updated to patched version specified in security advisory📡 Detection & Monitoring
Log Indicators:
- Unusual backup file uploads
- Failed backup validation attempts
- Suspicious restore operations
Network Indicators:
- Large backup file uploads to Moodle restore endpoints
SIEM Query:
source="moodle_logs" AND (event="backup_restore" OR event="file_upload") AND size>100MB