Authorization bypass through user-controlled key in Keycloak - CVE-2026-37978
Published: September 10, 2026
Vulnerability identifier: #VU148952
CSH Severity: Low
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-37978
CWE-ID: CWE-639
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to disclose personally identifiable information.
The vulnerability exists due to authorization bypass through a user-controlled key in the evaluate-scopes Admin API endpoints when invoking the endpoints with an arbitrary user ID parameter. A remote privileged user can submit an arbitrary user ID to view user identities and authorizations across the realm.
The issue affects administrators assigned the view-clients role.
Affected software
Keycloak
Red Hat build of Keycloak
Red Hat build of Keycloak
How to mitigate CVE-2026-37978
Install security update from vendor's website.
Keycloak - update to 26.6.2
Red Hat build of Keycloak - update to 26.4.12
Red Hat build of Keycloak - update to 26.4.12