What is CVE-2026-4633?

CVE-2026-4633 is a low-severity vulnerability in Red Hat Build Of Keycloak, classified under Generation of Error Message Containing Sensitive Information. CVSS score: 3.7/10. Published 2026-03-23.

How severe is CVE-2026-4633?

Low severity. CVSS v3 base score is 3.7 out of 10.

Information disclosure in Red Hat Build Of Keycloak

CVE-2026-4633

A flaw was found in Keycloak. A remote attacker can exploit differential error messages during the identity-first login flow when Organizations are enabled. This vulnerability allows an attacker to determine the existence of users, leading to information disclosure through user enumeration.

Published 2026-03-23 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 3.7 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (27.8th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 27.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.000

Affected products

Weakness classification (CWE)

CWE-209 — Generation of Error Message Containing Sensitive Information

References

access.redhat.com/security/cve/CVE-2026-4633 (vdb-entry, Vendor Advisory)
bugzilla.redhat.com/show_bug.cgi (issue-tracking, Exploit, Issue Tracking, Vendor Advisory)

Frequently asked questions

What is CVE-2026-4633?: CVE-2026-4633 is a low-severity vulnerability in Red Hat Build Of Keycloak, classified under Generation of Error Message Containing Sensitive Information. CVSS score: 3.7/10. Published 2026-03-23.
How severe is CVE-2026-4633?: Low severity. CVSS v3 base score is 3.7 out of 10.