Incorrect Authorization (CWE-863) in Kibana can lead to unauthorized disclosure, modification, and deletion of data via Accessing Functionality Not Properly Constrained by ACLs (CAPEC-1). Where two authenticated principals originating from different authentication realms share the same username value, one could read, modify, and delete the other's private Elastic AI Assistant Knowledge Base entries.
https://discuss.elastic.co/t/kibana-8-19-21-9-4-6-9-5-2-security-update-esa-2026-142/390093