Review reviewHigh

CVE-2026-9099

Red Hat Red Hat build of Keycloak 26.4, Red Hat build of Keycloak 26.4.13, Red Hat build of Keycloak 26.6

A flaw was found in Keycloak. A missing authorization check in the GroupResource.addChild() endpoint within the Admin REST API allows an authenticated user with limited administrative privileges to reparent any existing group. When Fine-Grained Admin Permissions v2 (FGAPv2) is enabled, an attacker with management rights over a single low-privilege group can reparent a highly privileged group (such as one possessing the realm-admin role) under their managed group. Because group permissions follow a hierarchical structure, this action unauthorizedly grants the attacker management and password...

CVSS: 7.7
EPSS: 0.29%
CISA KEV: Not listed
Published: 2026.06.26

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.29%

Technical severityCVSS 7.7

Vulnerability overview

Affected product and versions

Product: Red Hat Red Hat build of Keycloak 26.4, Red Hat build of Keycloak 26.4.13, Red Hat build of Keycloak 26.6
Affected versions: >= 26.4 < 26.4.13, >= 26.6 < 26.6.4
Fixed versions: 26.4.13, 26.6.4

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that Red Hat Red Hat build of Keycloak 26.4, Red Hat build of Keycloak 26.4.13, Red Hat build of Keycloak 26.6 and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:N
CWE: CWE-639