Description
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.
Affected products
redhat: build of keycloak
References3
- access.redhat.com/security/cve/CVE-2026-4633 Vendor Advisory
- bugzilla.redhat.com/show_bug.cgi?id=2450247 ExploitIssue TrackingVendor Advisory
- access.redhat.com/errata/RHSA-2026:19596
Metrics
- CVSS 3.1
-
3.7
LOW
Score source: NVD
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N - EPSS — exploit probability
- 0% percentile: 38 · as of 12 November 2026
- CWE
- CWE-209
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.