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
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | Red Hat build of Keycloak 26.4.12 | — | — |
| Red Hat | Red Hat Build of Keycloak | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | keycloak-26.4-iamguarded-compat | No fix yet | — |
| Wolfi rolling | keycloak-26.5 +1 | 26.5.7-r0 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Maven | org.keycloak:keycloak-services | >= 26.5.0, < 26.6.1 | 26.6.1 | GHSA-rhgq-f8x5-j2jc |
| Maven | org.keycloak:keycloak-services | < 26.4.12 | 26.4.12 | GHSA-rhgq-f8x5-j2jc |
Advisories 1
- WID-SEC-2026-0821 Keycloak: Mehrere Schwachstellen BSI CERT-Bund (WID) · Sep 30, 2026
References
- RHSA-2026:19596 vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-4633 vdb-entry
- RHBZ#2450247 issue-tracking