Keycloak on Red Hat Group Members Endpoint insufficient granularity of access control

Summaryinfo

A vulnerability was found in Keycloak on Red Hat. It has been classified as problematic. This vulnerability affects unknown code of the component Group Members Endpoint. Performing a manipulation results in insufficient granularity of access control. This vulnerability is reported as CVE-2026-9088. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Keycloak on Red Hat (unknown version). This affects an unknown code block of the component Group Members Endpoint. The manipulation with an unknown input leads to a insufficient granularity of access control vulnerability. CWE is classifying the issue as CWE-1220. The product implements access controls via a policy or other feature with the intention to disable or restrict accesses (reads and/or writes) to assets in a system from untrusted agents. However, implemented access controls lack required granularity, which renders the control policy too broad because it allows accesses from unauthorized agents to the security-sensitive assets. This is going to have an impact on confidentiality. The summary by CVE is:

A flaw was found in org.keycloak.services. An administrator with delegated access to read group memberships and users can bypass user profile permissions by accessing the group members endpoint. This allows the administrator to view user attributes that are explicitly configured to be denied, leading to information disclosure.

The advisory is shared at access.redhat.com. This vulnerability is uniquely identified as CVE-2026-9088 since 05/20/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Additional levels of successful authentication are required for exploitation. Neither technical details nor an exploit are publicly available.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-34790). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Name

• Keycloak

License

• open-source

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion