Improper Input Validation in Kibana Fleet Leading to Privilege Escalation
Improper Input Validation (CWE-20) in the Kibana Fleet agent policy management feature can lead to privilege escalation. An authenticated user with Fleet management privileges can manipulate agent policy configuration by injecting values into a configuration override mechanism that is not adequately validated. An attacker can cause Elastic Agents to be issued API keys with elevated Elasticsearch privileges, potentially granting unauthorized read and write access to sensitive Elasticsearch security indices beyond what is intended for the Fleet management role.
Affected Versions:
- 8.x: All versions from 8.0.0 up to and including 8.19.15
- 9.x:
- All versions from 9.0.0 up to and including 9.3.4
- All versions from 9.4.0 up to and including 9.4.1
Affected Configurations:
- Kibana deployments with the Fleet feature enabled where users have been granted the Fleet management application privilege (fleet-all) are affected.
Solutions and Mitigations:
The issue is resolved in versions 8.19.16, 9.3.5, and 9.4.2.
For Users that Cannot Upgrade:
- Restrict the fleet-all Kibana application privilege.
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: High ( 7.2 ) - AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
CVE ID: CVE-2026-49095
Problem Type: CWE-20 - Improper Input Validation