CVE-2026-9798 MEDIUM

CVE-2026-9798: Keycloak: keycloak: brute-force protection bypass in ciba flow

Vendor Red Hat
Product Red Hat Build of Keycloak
Weakness CWE-305
Published May 28, 2026
Last update May 29, 2026

CVSS base score

4.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction Required
Confidentiality Low
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

What the vulnerability does

01Description

A flaw was found in Keycloak, an open-source identity and access management solution. When a user account is temporarily locked due to repeated failed login attempts, an attacker with valid client credentials can exploit the Client-Initiated Backchannel Authentication (CIBA) flow to bypass this brute-force protection. This allows continued authentication attempts and token issuance even when the account should be locked, potentially enabling further unauthorized access attempts.

Key dates

02Disclosure timeline

May 28, 2026 CVE published
May 29, 2026 Record updated