Auth bypass in Red Hat Build Of Keycloak

CVE-2026-18207

A flaw was found in the client policy enforcement mechanism of Keycloak. The issue occurs when the system checks group membership by name instead of a unique identifier. An attacker with client management privileges could bypass security policies by joining a group with a matching name in a different part of the group hierarchy, potentially allowing them to register or update clients without following required security hardening profiles.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.003 (24.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 24th percentile — 24.4% 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-2026-18207: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-18207?
CVE-2026-18207 is a medium-severity vulnerability in Red Hat Build Of Keycloak, classified under Improper Authorization. CVSS score: 6.5/10. Published 2026-07-29.
How severe is CVE-2026-18207?
Medium severity. CVSS v3 base score is 6.5 out of 10.