CVE-2026-9099
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.49%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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-reset capabilities over the members of the targeted privileged group. An attacker can exploit this to reset an administrator's password, compromise the account, and achieve a full realm takeover, leading to a complete compromise of confidentiality, integrity, and availability.
- CVSS 3.1
- 7.7 HIGHCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:N
- EPSS
- 0.49% probability · 41th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-639
- Affected
- redhat/build of keycloak
- Source
- secalert@redhat.com
References
- https://access.redhat.com/errata/RHSA-2026:30049Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:30050Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:30083Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:30084Third Party Advisory
- https://access.redhat.com/security/cve/CVE-2026-9099Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2480182Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:30049Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:30050Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:30083Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:30084Third Party Advisory
- https://access.redhat.com/security/cve/CVE-2026-9099Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2480182Third Party Advisory
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-9099.jsonThird Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.