CVE-2026-97311 in Keycloak
Summary
by MITRE • 09/24/2026
A flaw was found in the Admin REST API of Keycloak, an identity and access management solution. The endpoints used to retrieve groups associated with a specific role do not properly check for individual group visibility permissions. This allows a delegated administrator with basic search privileges to view detailed information about all groups assigned to a role, bypassing intended security restrictions that should limit their view to specific groups.
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Analysis
by VulDB Data Team • 09/24/2026
The vulnerability identified in Keycloak represents a critical authorization failure within the Admin REST API, specifically affecting the endpoints responsible for retrieving group associations linked to particular roles. As an identity and access management solution, Keycloak relies heavily on granular permission models to ensure that administrative tasks are performed only by users with appropriate privileges. In this scenario, the flaw lies in the server-side logic that processes requests from delegated administrators who possess basic search capabilities. While these administrators are intended to have limited visibility restricted to specific groups they manage or are assigned to, the API endpoint fails to enforce individual group visibility permissions when fetching data related to a role. This oversight allows an attacker with low-level privileges to bypass security controls and access detailed information about all groups associated with any given role, regardless of whether those groups fall within their authorized scope.
From a technical perspective, this issue is classified as an Insecure Direct Object Reference or more specifically, a Broken Access Control vulnerability where the application fails to properly verify that the requesting user has permission to perform the action on the specific resource being accessed. The root cause stems from insufficient validation of group-level permissions during the role-group association retrieval process. Instead of filtering results based on the caller's assigned group memberships and visibility rules, the system returns a comprehensive list of all groups tied to the specified role identifier. This behavior contradicts the principle of least privilege, which dictates that users should only have access to the data necessary for their specific function. The lack of proper authorization checks at this layer effectively neutralizes the security boundaries established by Keycloak's fine-grained administration model, allowing unauthorized enumeration and disclosure of organizational structure details.
The operational impact of this vulnerability is significant in environments where sensitive group structures or membership lists are considered confidential information. An attacker exploiting this flaw can map out the entire identity landscape associated with specific roles, potentially identifying high-privilege groups, service accounts, or administrative units that were not intended to be visible to lower-level administrators. This intelligence gathering phase can facilitate further attacks, such as privilege escalation attempts, lateral movement within the network by targeting members of sensitive groups, or social engineering campaigns based on revealed organizational hierarchies. Furthermore, in multi-tenant deployments where different organizations share a Keycloak instance, this flaw could lead to cross-tenant data leakage if role definitions are not strictly isolated per tenant context, thereby compromising confidentiality and integrity across multiple independent entities.
This vulnerability aligns with CWE-269, Improper Privilege Management, as it involves an actor obtaining privileges or accessing resources beyond their assigned level of authority. It also maps directly to the MITRE ATT&CK technique T1087.004, Account Discovery: Domain Group Accounts, which describes adversaries discovering group accounts within a domain environment to identify high-value targets and understand the security structure. By exposing detailed group information without proper access control verification, Keycloak inadvertently aids attackers in mapping out administrative boundaries and identifying potential entry points for deeper compromise. The severity is heightened by the fact that it affects the Admin REST API, which is often exposed internally or externally depending on deployment configurations, increasing the attack surface available to malicious actors who have already gained a foothold with basic search privileges.
Mitigation strategies must focus on enforcing strict authorization checks at the point of data retrieval within the Keycloak server codebase. Developers should ensure that every group object returned by the role-group association endpoint is validated against the requesting user's specific permissions and visibility settings before inclusion in the response payload. This involves implementing a filter mechanism that cross-references each group ID with the caller’s authorized group list, ensuring that only groups explicitly permitted for viewing are included in the results. Additionally, security testing procedures should be enhanced to include automated checks for broken access control vulnerabilities within administrative APIs, utilizing tools that simulate low-privilege user actions against high-sensitivity endpoints. Organizations currently running vulnerable versions of Keycloak should apply vendor-provided patches immediately and review their delegation configurations to ensure that delegated administrators are granted only the minimum necessary permissions required for their operational duties, thereby reducing the blast radius in case of future exploits.