Authorization Bypass Through User-Controlled Key (CWE-639) in Kibana can lead to unauthorized disclosure, modification, and deletion of data via Accessing Functionality Not Properly Constrained by ACLs (CAPEC-1). An authenticated user granted the Timeline feature privilege in a Kibana space could enumerate, read, modify, and delete draft Timeline objects belonging to other users in the same space. Read access is sufficient for enumeration and disclosure; the Timeline write privilege is required for modification and deletion.