Vulnerability · Published Mar 23, 2026 · Assigned by redhat
CVE-2026-4633Keycloak: keycloak: user enumeration via differential error messages
Low 3.7
In plain English
A low-severity security flaw in Red Hat Build of Keycloak from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 37% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)3.7Low
Exploit odds (30 days)0.4%top 63.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Maven | org.keycloak:keycloak-services | 26.6.1 | GHSA-rhgq-f8x5-j2jc |
| Maven | org.keycloak:keycloak-services | 26.4.12 | GHSA-rhgq-f8x5-j2jc |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Red Hat | Red Hat build of Keycloak 26.4.12 | see references |
| Red Hat | Red Hat Build of Keycloak | see references |
Weakness: CWE-209 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
References
- RHSA-2026:19596 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-4633 vdb-entry, x_refsource_REDHAT
- RHBZ#2450247 issue-tracking, x_refsource_REDHAT