CVE-2026-25040: Budibase Privilege Escalation Vulnerability

CVE-2026-25040 Overview

CVE-2026-25040 is a privilege escalation vulnerability in Budibase, a popular low-code platform for creating internal tools, workflows, and admin panels. The vulnerability allows a Creator-level user, who normally has no UI permission to invite users, to manipulate API requests and invite new users with any role including Admin, Creator, or App Viewer. The attacker can also assign these users to any group within the organization, leading to full privilege escalation and potential complete takeover of the workspace or organization.

This vulnerability is classified under CWE-863 (Incorrect Authorization), indicating that the application fails to properly verify that a user has the necessary permissions before allowing sensitive operations.

Critical Impact

Attackers with Creator-level access can bypass UI restrictions and escalate privileges to Admin level, potentially leading to complete organizational takeover through unauthorized user invitation and role assignment.

Affected Products

• Budibase versions up to and including 3.26.3
• All Budibase deployments using vulnerable versions with Creator-level users

Discovery Timeline

• January 29, 2026 - CVE-2026-25040 published to NVD
• January 29, 2026 - Last updated in NVD database

Technical Details for CVE-2026-25040

Vulnerability Analysis

This vulnerability represents an authorization bypass flaw where the Budibase platform enforces role-based access controls only at the UI layer, failing to implement equivalent restrictions on the underlying API endpoints. Creator-level users, who are intended to have limited permissions for building applications but not managing users, can circumvent UI-based restrictions by directly crafting and sending API requests to user invitation endpoints.

The root issue lies in the disconnect between frontend permission enforcement and backend API authorization checks. While the UI correctly hides user invitation functionality from Creator-level accounts, the backend API endpoints responsible for user management do not adequately validate the requesting user's permission level before processing invitation requests.

Root Cause

The vulnerability stems from improper authorization validation in the Budibase API layer. The application relies on client-side UI restrictions to limit Creator-level users from inviting new users, but fails to implement corresponding server-side authorization checks on the relevant API endpoints. This allows authenticated users to bypass intended access controls by directly interacting with the API, circumventing the frontend permission model entirely.

This is a classic example of CWE-863 (Incorrect Authorization), where security decisions are made based on UI-level controls rather than proper server-side validation.

Attack Vector

The attack exploits the network-accessible API endpoints in Budibase. An authenticated attacker with Creator-level privileges can intercept or craft HTTP requests to the user invitation API endpoint, modifying parameters to:

1. Invite new users to the organization
2. Assign arbitrary roles (Admin, Creator, or App Viewer) to invited users
3. Add users to any group within the organization

The attack requires no user interaction and can be performed by any authenticated Creator-level user with network access to the Budibase instance. The technical details and a proof-of-concept script are available in the GitHub Security Advisory and associated documentation.

Detection Methods for CVE-2026-25040

Indicators of Compromise

• Unexpected user invitations appearing in the organization, particularly with Admin or elevated roles
• API request logs showing user invitation attempts from Creator-level accounts
• New user accounts being added to sensitive groups without corresponding UI activity
• Anomalous patterns in authentication logs showing new users created by non-Admin accounts

Detection Strategies

• Monitor API access logs for user invitation endpoint calls from accounts without Admin privileges
• Implement alerts for role assignments that exceed the requesting user's permission level
• Review audit logs for discrepancies between UI activity and API-level operations
• Deploy application-layer firewalls or API gateways to validate authorization headers on sensitive endpoints

Monitoring Recommendations

• Enable comprehensive API request logging for all user management endpoints
• Configure alerts for bulk user invitations or rapid role changes
• Implement periodic audits of user roles and group memberships to detect unauthorized escalations
• Monitor for the presence of known PoC scripts or tools targeting this vulnerability

How to Mitigate CVE-2026-25040

Immediate Actions Required

• Audit all Creator-level accounts for suspicious activity or unauthorized user invitations
• Review recently created user accounts for unexpected role assignments
• Restrict network access to Budibase API endpoints where possible
• Consider temporarily revoking Creator-level access until a patch is available
• Implement API gateway rules to block unauthorized user invitation requests

Patch Information

As of the publication date (January 29, 2026), no known fixed versions are available from Budibase. Organizations should monitor the GitHub Security Advisory for patch release announcements.

Workarounds

• Implement network-level access controls to restrict API endpoint access to trusted sources only
• Deploy a reverse proxy or API gateway to enforce additional authorization checks on user management endpoints
• Reduce the number of Creator-level accounts to minimize attack surface
• Enable comprehensive audit logging and configure real-time alerts for user management operations
• Consider using an identity provider with additional access controls for user provisioning

# Example: Restrict API access via nginx reverse proxy
# Add to your nginx configuration for Budibase
location /api/global/users/invite {
    # Only allow requests from Admin IP ranges
    allow 10.0.0.0/8;
    deny all;
    
    proxy_pass http://budibase-backend;
}