CVE-2026-16108: redhat build_of_keycloak

Vulnerability summary

CVE-2026-16108 is a medium (CVSS 6.5) vulnerability in redhat build_of_keycloak. EPSS estimates a 0.37% chance of exploitation in the next 30 days, higher than 29.3% of scored vulnerabilities.

Timeline

1. 17-07-2026
   PublishedVulnerability first disclosed.
2. 16-09-2026
   Last modifiedVulnerability information updated.

Description

A flaw was found in the default-groups REST endpoint and realm representation of Keycloak. This component is responsible for managing groups that are automatically assigned to new users within a realm. The issue allows a delegated administrator with realm-viewing permissions to see the names and identifiers of hidden default groups, even if they lack the specific permissions to view those groups. This can lead to the exposure of sensitive organizational structures or internal group names.

• CWE-1220Insufficient Granularity of Access ControlThe 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.
• CWE-200Exposure of Sensitive Information to an Unauthorized ActorThe product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.