Authenticated file disclosure via traversed backup identifier

Path traversal in qBit Manage 4.5.0 through 4.5.3 allows remote authenticated users to read arbitrary server files through its web API. The restore_config_from_backup endpoint joins the unvalidated backup_id value to the backup directory, so parent-directory sequences resolve outside that directory. Exploitation requires the web API to be enabled and reachable with authentication, and disclosure is limited to files readable by the qBit Manage process.