GCVE-110-CERTCC-2026-889462

### Overview Casdoor is an open-source Access Management (IAM) platform used to manage web applications. An authorization bypass vulnerability affects Casdoor versions 3.115.0 and earlier. The vulnerability allows a non-global organization administrator to perform unauthorized administrative actions against arbitrary organizations by exploiting inconsistent object resolution between the authorization layer and downstream controllers. In multi-tenant deployments, an attacker with administrative privileges within a single organization can bypass tenant isolation and perform administrative operations against other organizations. ### Description **CVE-2026-15630.** The vulnerability stems from a desynchronization between authorization and action in multiple `POST /api/{add,delete}- endpoints (e.g., /api/add-user, /api/delete-user, /api/add-permission)`. While the global authorization filter (`routers/authzfilter.go`) correctly uses the `?id=` URL query parameter as the authoritative target for authorization decisions, the affected controllers (`controllers/user.go`, `controllers/permission.go`, etc.) ignore `?id=` and operate solely on the owner and name fields in the JSON request body. As a result, authorization is evaluated against one object while the requested operation is executed against another, allowing an authenticated organization administrator (`IsAdmin=true`) to perform unauthorized administrative actions across tenant boundaries. ### Impact An attacker with administrative privileges in a single organization can compromise the isolation guarantees of a multi-tenant Casdoor deployment. Depending on the exposed endpoints and deployment configuration, successful exploitation can allow for administrative operations including user management, privilege management and disruption of single sign-on (SSO) or Security Assertion Markup Language (SAML) identity. The overall impact can escalate to a complete compromise of tenant isolation and, in some deployment scenarios, potential compromise of the entire Casdoor instance. ### Solution Unfortunately, we were unable to reach Casdoor to coordinate this vulnerability. Therefore, at the time of this publication, no vendor patch is known to be available. If upgrading to a fixed release is not yet possible, organizations can consider the following mitigations: * Enforce least privilege by minimizing the number of accounts with `IsAdmin=true`, disabling any workflows that automatically grant admin privilege * Require multi-factor authentication (MFA) for all administrative accounts and/or administrative actions * Alert on cross-organization administrative activity, including: * Creation of administrator accounts * Deletion of users belonging to other organizations * Modification of permissions across organizational boundaries using wildcard `resources=[""]` or `actions=[""]` permissive Casbin rules. * Investigate unexplained reductions in user counts or administrative objects within any organization. ### Acknowledgements Thank you to Louis Sanchez of Voke Cyber for reporting this vulnerability. This document was written by Alexander Curtis.