Low severity · published Mar 23, 2026
CVE-2026-4633
Keycloak: keycloak: user enumeration via differential error messages
3.7
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 36% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RH
Red Hat Build of Keycloak · Red Hat
All versions, or not specified · source: vendor
BO
Build OF Keycloak · Redhat
All versions, or not specified · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-4633
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-4633
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:19596
Vendor Advisory
https://access.redhat.com/security/cve/CVE-2026-4633
Exploit
https://bugzilla.redhat.com/show_bug.cgi?id=2450247
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