Auth bypass in Red Hat Build Of Keycloak

CVE-2026-117627

A flaw was found in the JWT Authorization Grant implementation of the keycloak-services component. When an OIDC or Google identity provider is configured with specific login restrictions, such as claim filtering, these checks are correctly applied during standard browser logins but are skipped during the JWT-based grant flow. This allows an authenticated client to obtain access tokens for a user even if their identity provider claims should have blocked the login.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (16.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 16.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

The 30-day trend appears once there are two daily scores.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-117627?
CVE-2026-117627 is a medium-severity vulnerability in Red Hat Build Of Keycloak, classified under Missing Authorization. CVSS score: 5.4/10. Published 2026-10-29.
How severe is CVE-2026-117627?
Medium severity. CVSS v3 base score is 5.4 out of 10.