CVE-2026-9099
HighCVSS 7.7Exploitation Probability (EPSS)
Low risk19th percentile — higher than 19% of all known CVEs
Summary
A missing authorization check in the Keycloak GroupResource.addChild() endpoint allows an authenticated user with limited admin privileges to reparent any group. With FGAPv2 enabled, an attacker can move a high-privilege group under their control.
Risk Assessment
The attacker gains unauthorized management and password-reset capabilities over privileged group members, potentially leading to admin account compromise and full realm takeover, affecting confidentiality, integrity, and availability.
Recommendation
Update Keycloak to the patched version immediately and review FGAPv2 permission configurations to restrict group reparenting.
Original NVD description (English source)
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.