---
id: CVE-2026-4633
aliases:
  - GHSA-rhgq-f8x5-j2jc
title: Keycloak's identity-first login flow exposes user information
summary: Keycloak's identity-first login flow exposes user information
severity: low
cvss: 3.7
cwe:
  - CWE-209
vendor: keycloak
product: 'org.keycloak:keycloak-services'
ecosystem: maven
affected:
  - 'org.keycloak:keycloak-services >= 26.5.0, < 26.6.1'
  - 'org.keycloak:keycloak-services < 26.4.12'
patched:
  - 'org.keycloak:keycloak-services 26.6.1'
  - 'org.keycloak:keycloak-services 26.4.12'
published: '2026-03-23'
updated: '2026-10-23'
sourceUpdated: '2026-10-23T00:32:50Z'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-rhgq-f8x5-j2jc'
references:
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-4633'
  - url: 'https://access.redhat.com/security/cve/CVE-2026-4633'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2450247'
  - url: 'https://github.com/keycloak/keycloak/issues/47619'
  - url: >-
      https://github.com/keycloak/keycloak/commit/b137016cc6dcfd9f59b2aa2e6d73af8b0ebf7c6e
  - url: >-
      https://github.com/keycloak/keycloak/commit/b4558a874fa79341404ae4d2d8f240f22bfed340
  - url: 'https://github.com/keycloak/keycloak/pull/47635'
  - url: 'https://access.redhat.com/errata/RHSA-2026:19596'
  - url: 'https://github.com/advisories/GHSA-rhgq-f8x5-j2jc'
tags:
  - ghsa
  - maven
  - cve.org
epss: 0.00379
epssPercentile: 0.30704
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-03-23T15:07:15.419255Z'
ingestedAt: '2026-10-22T22:00:50.444Z'
---

## Overview

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

- `org.keycloak:keycloak-services >= 26.5.0, < 26.6.1`
- `org.keycloak:keycloak-services < 26.4.12`

## Remediation

Upgrade to a patched release:

- `org.keycloak:keycloak-services 26.6.1`
- `org.keycloak:keycloak-services 26.4.12`