ArcadeDB before 26.8.1 fails to bind the authenticated principal (setCurrentUser) on its batch and time-series HTTP handlers. Because no principal is bound on the worker thread, the engine's fine-grained per-type ACL layer (LocalBucket.checkPermissionsOnFile) does not execute for these handlers. In deployments that use per-type or per-group ACLs, a user with database access but only limited per-type permissions can read from and write to types they are not authorized to access by submitting requests to the batch/time-series endpoints. Deployments that rely solely on database-level access control are not affected.