Auth bypass in Red Hat Build Of Keycloak

CVE-2026-37978

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 cro…

Vulnerability class: IDOR (Insecure Direct Object Reference)

EPSS: 0.000 (2.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.9 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-37978?
CVE-2026-37978 is a medium-severity vulnerability in Red Hat Build Of Keycloak, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 4.9/10. Published 2026-05-19.
How severe is CVE-2026-37978?
Medium severity. CVSS v3 base score is 4.9 out of 10.