Vulnerability · Published Jun 25, 2026 · Assigned by redhat

CVE-2026-9099Keycloak: group-admin escalation to realm-admin

High 7.7

In plain English

A high-severity authorization bypass via user-controlled key in Red Hat build of Keycloak 26.4 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities).

Severity (CVSS 3.1)7.7High
Exploit odds (30 days)0.5%top 57.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

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

References