n8n: Cross-Tenant Project-Member PII Disclosure via Missing Per-Project Scope Check on Role Assignment Endpoints

Impact

The endpoints /rest/roles/:slug/assignments and /rest/roles/:slug/assignments/:projectId/members checked only that the caller could manage the role type, not that they could see the project named in the request. A user holding role-management permission could therefore name any project on the instance and read back its members' names and email addresses. The patch adds a project-access check to both routes, hiding projects the caller cannot see and returning not-found for a project it cannot list.

Patches

The issue has been fixed in n8n versions 2.38.2 and 2.37.7. Users should upgrade to one of these versions or later to remediate the vulnerability.

Workarounds

If upgrading is not immediately possible, administrators should consider the following temporary mitigations:

• Restrict n8n instance access to fully trusted users only.
• Audit and revoke any custom global roles that carry the role:manageProject scope, limiting that scope to fully trusted users only.

These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.