Auth bypass in Red Hat Build Of Keycloak

CVE-2026-9791

A flaw was found in Keycloak. An authenticated user with existing organization membership can exploit this flaw by accessing user-facing APIs, such as the account API or by requesting an OpenID Connect (OIDC) token with the 'organization' scope. This allows organization metadata to be disclosed in tokens, even after an administrator has explicitly disabled the Organizations feature, potentially leading to incorrect authorization decisions by resource servers.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (28.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 28.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-9791: held from 0.002 to 0.004.

EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-9791?
CVE-2026-9791 is a medium-severity vulnerability in Red Hat Build Of Keycloak, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2026-05-28.
How severe is CVE-2026-9791?
Medium severity. CVSS v3 base score is 4.3 out of 10.