In OpenStack Blazar before 17.0.1, the V2 lease listing operation (GET /v2/leases) returns leases for every project without enforcing project scoping or an administrator-only policy. Any authenticated user with access to the Blazar REST API can enumerate leases belonging to other tenants, exposing lease IDs, reservation IDs, resource IDs, and reservation metadata. The exposed lease IDs also enable the object-level authorization bypass tracked in the companion request, allowing an attacker to then modify or delete the enumerated leases.