In OpenStack Blazar before 17.0.1, the V2 lease API does not enforce object-level authorization on its update and delete operations (PUT /v2/leases/{lease_id} and DELETE /v2/leases/{lease_id}). The policy authorize() wrapper attempts to load the target lease to build the authorization target from its owner, but it looks up the lease under the keyword "lease_id" whereas the controller methods name the parameter "id" (and the wsme_pecan.wsexpose wrapper delivers it positionally). The lookup returns None, and thus authorization falls back to the requesting user's own project_id/user_id instead of the target lease owner. Any authenticated user who knows a lease ID can therefore modify or delete leases belonging to other users and projects, bypassing the intended ownership check.