Incorrect Authorization in Kibana Leading to Unauthorized Disclosure, Modification, and Deletion of Data
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.
Affected Versions:
- 8.x: All versions from 8.19.11 up to and including 8.19.20
- 9.x:
- All versions from 9.3.0 up to and including 9.4.5
- All versions from 9.5.0 up to and including 9.5.1
Affected Configurations:
Deployments that have multiple authentication realms configured, where distinct authenticated principals in separate realms share the same username value, and where those principals hold a role granting access to the Elastic AI Assistant feature. Deployments configured with only a single authentication realm are not affected.
Solutions and Mitigations:
The issue is resolved in Kibana versions 8.19.21, 9.4.6, and 9.5.2.
For Users that Cannot Upgrade:
There are no workarounds for this vulnerability.
Indicators of Compromise (IOC)
No specific indicators of compromise have been identified for this vulnerability.
Elastic Cloud Serverless
Due to our continuous deployment and patching model, the vulnerability described in this security advisory was remediated in our Elastic Cloud Serverless offering before the public disclosure.
Severity: CVSSv3.1: Medium ( 4.2 ) - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N
CVE ID: CVE-2026-78606
Problem Type: CWE-863 - Incorrect Authorization
Impact: CAPEC-1 - Accessing Functionality Not Properly Constrained by ACLs