Incorrect Authorization in Kibana Agent Builder Leading to Disclosure and Tampering of Private Agents
Kibana Agent Builder determines whether a caller owns a private agent by comparing a stable user identifier when one is recorded, and falling back to a comparison of the username when it is not. A username is not unique across Elasticsearch authentication realms, so two distinct principals that share a username in different realms are treated as the same owner. This discloses the configuration and instructions of an agent the caller does not own, and allows that agent to be altered or removed.
Affected Versions:
- All versions from 9.4.0 up to and including 9.4.4
- Version 9.5.0
Affected Configurations:
All configurations that use multiple authentication realms where the user has control over their selected username.
Solutions and Mitigations:
The issue is resolved in Kibana versions 9.4.5 and 9.5.1.
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: High ( 7.1 ) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
CVE ID: CVE-2026-72643
Problem Type: CWE-863 - Incorrect Authorization