An issue was discovered by Elastic, whereby the Detection Engine Search API does not respect Document-level security (DLS) or Field-level security (FLS) when querying the .alerts-security.alerts-{space_id} indices. Users who are authorized to call this API may obtain unauthorized access to documents if their roles are configured with DLS or FLS against the aforementioned index.
https://www.elastic.co/community/security
https://discuss.elastic.co/t/kibana-8-12-1-security-update-esa-2024-01/352686