Auth bypass in Red Hat Build Of Keycloak

CVE-2026-4630

A flaw was found in Keycloak. An authenticated client could exploit an Insecure Direct Object Reference (IDOR) vulnerability in the Authorization Services Protection API endpoint. By knowing or obtaining a resource's unique identifier (UUID) belonging to another Resource Server within the same realm, the client could bypass authorization checks. This allows the client to perform unauthorized GET, PUT, and DELETE operations on resources, leading to information disclosure and potential unauthorized modification or deletion of data.

Vulnerability class: IDOR (Insecure Direct Object Reference)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.004 (29.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 29.2% 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-2026-4630: held from 0.003 to 0.004.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-4630?
CVE-2026-4630 is a medium-severity vulnerability in Red Hat Build Of Keycloak, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 6.8/10. Published 2026-05-19.
How severe is CVE-2026-4630?
Medium severity. CVSS v3 base score is 6.8 out of 10.