CVE-2026-25859: Wekan Auth Bypass Vulnerability

CVE-2026-25859 Overview

CVE-2026-25859 is an Authorization Bypass vulnerability affecting Wekan, an open-source kanban board application. Versions prior to 8.20 allow non-administrative users to access migration functionality due to insufficient permission checks, potentially resulting in unauthorized migration operations. This vulnerability is classified as CWE-863 (Incorrect Authorization).

Critical Impact

Non-administrative users can exploit insufficient permission checks to access and execute migration functionality, potentially leading to unauthorized data manipulation or system disruption.

Affected Products

• Wekan versions prior to 8.20
• wekan_project wekan (all platforms)
• Self-hosted Wekan deployments with multi-user access

Discovery Timeline

• 2026-02-07 - CVE CVE-2026-25859 published to NVD
• 2026-02-10 - Last updated in NVD database

Technical Details for CVE-2026-25859

Vulnerability Analysis

This authorization bypass vulnerability stems from insufficient permission validation in Wekan's migration functionality. The application fails to properly verify whether a user has administrative privileges before allowing access to migration operations. This allows any authenticated user, regardless of their assigned role, to invoke migration functions that should be restricted to administrators only.

The vulnerability is exploitable over the network by any authenticated user, requiring no user interaction. Successful exploitation could result in unauthorized modification of application data through migration operations, potentially causing data integrity issues and limited availability impact.

Root Cause

The root cause is CWE-863: Incorrect Authorization. The migration manager component was accessible from the general client-side code without adequate permission enforcement. The migration functionality was imported directly into the main client startup sequence (/client/lib/migrationManager) and exposed through the board body template without checking if the current user has administrative privileges. This architectural flaw allowed any authenticated user to trigger migration processes.

Attack Vector

The attack vector is network-based, requiring only low-privilege authentication. An attacker with a standard user account can access the migration functionality by navigating to the board interface where the migration progress component is rendered. The lack of server-side and client-side permission checks means the migration manager can be invoked by manipulating client-side state or directly calling exposed migration functions.

The following code shows the security patch that addresses this vulnerability by relocating migration functionality to admin-only settings:

 import '/client/components/boardConversionProgress';
 
 // Import migration manager and progress UI
-import '/client/lib/migrationManager';
-import '/client/components/migrationProgress';
+import '/client/lib/attachmentMigrationManager';
+import '/client/components/settings/migrationProgress';
 
 // Import cron settings
 import '/client/components/settings/cronSettings';

Source: GitHub Commit Update

The template change removes migration progress from the general board view:

 template(name="board")
   
-  if isMigrating.get
-    +migrationProgress
-  else if isConverting.get
+  if isConverting.get
     +boardConversionProgress
   else if isBoardReady.get
     if currentBoard

Source: GitHub Commit Update

Detection Methods for CVE-2026-25859

Indicators of Compromise

• Unexpected migration operations appearing in application logs from non-administrative user sessions
• Database schema changes or data migrations initiated outside of scheduled maintenance windows
• Access logs showing non-admin users interacting with migration-related endpoints or components
• Unusual activity patterns in attachment or data migration processes

Detection Strategies

• Monitor application logs for migration function invocations and correlate with user privilege levels
• Implement audit logging to track all migration-related API calls with associated user context
• Review web server access logs for requests to migration-related routes from standard user sessions
• Deploy application-level monitoring to detect unauthorized access to administrative functions

Monitoring Recommendations

• Enable detailed audit logging for all administrative functions in Wekan
• Configure alerts for migration operations initiated outside of authorized maintenance windows
• Implement role-based access control monitoring to detect privilege boundary violations
• Review user activity logs regularly for anomalous access patterns to restricted functionality

How to Mitigate CVE-2026-25859

Immediate Actions Required

• Upgrade Wekan to version 8.20 or later immediately
• Review application logs for any unauthorized migration operations that may have occurred
• Audit user accounts and verify proper role assignments
• Temporarily restrict access to the Wekan instance if immediate patching is not possible

Patch Information

The vulnerability has been addressed in Wekan version 8.20. The fix relocates migration functionality from the general client-side code to the admin settings module, ensuring proper permission enforcement. The security patch is available via the GitHub Commit. Additional information is available at the Wekan Official Website and the VulnCheck Advisory Report.

Workarounds

• Restrict network access to Wekan instances to trusted IP ranges until patching is complete
• Implement additional authentication layers such as VPN or reverse proxy with access controls
• Review and minimize the number of user accounts with any level of access to the system
• Consider temporarily disabling user registration and limiting new account creation

# Example: Restrict Wekan access using nginx reverse proxy
# Add to nginx server block to limit access by IP
location / {
    allow 192.168.1.0/24;
    allow 10.0.0.0/8;
    deny all;
    proxy_pass http://localhost:3000;
}