CVE-2026-37978: Keycloak: org.keycloak.services: keycloak: information disclosure via evaluate-scopes admin api

Severity: medium (CVSS 4.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-19 · updated 2026-10-25
Weakness: CWE-639

Description

A flaw was found in Keycloak. A low-privilege administrator with the 'view-clients' role can exploit this by invoking the 'evaluate-scopes' Admin API endpoints with an arbitrary user ID (userId) parameter. This vulnerability allows for cross-role personally identifiable information (PII) leakage, enabling unauthorized visibility into user identities and authorizations across the realm. Exploitation is possible remotely via network access to the Admin API.

Affected products

Red Hat build of Keycloak 26.4: before 26.4.12 — fixed in 26.4.12

How to fix

Upgrade to a fixed version: Red Hat build of Keycloak 26.4 26.4.12. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-37978 or the next vulnerability affects your stack