CVE-2026-9798
Keycloak CIBA Flow Bypasses Account Lockout Protection
Publication date: 2026-05-28
Last updated on: 2026-05-28
Assigner: Red Hat, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| redhat | keycloak | * |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-305 | The authentication algorithm is sound, but the implemented mechanism can be bypassed as the result of a separate weakness that is primary to the authentication error. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in Keycloak, an open-source identity and access management solution. It occurs when a user account is temporarily locked due to repeated failed login attempts. An attacker who has valid client credentials can exploit the Client-Initiated Backchannel Authentication (CIBA) flow to bypass this brute-force protection mechanism.
By exploiting this flaw, the attacker can continue making authentication attempts and receive token issuance even though the account should be locked, potentially allowing unauthorized access attempts to proceed.
How can this vulnerability impact me? :
This vulnerability can impact you by allowing an attacker to bypass account lockout protections designed to prevent brute-force attacks. As a result, unauthorized users may continue attempting to authenticate and obtain tokens, increasing the risk of unauthorized access to your systems or data.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The vulnerability in Keycloak allows an attacker to bypass brute-force protection mechanisms, potentially enabling unauthorized access attempts even when user accounts are locked. This could lead to unauthorized access to sensitive personal or protected health information.
Such unauthorized access risks may impact compliance with standards and regulations like GDPR and HIPAA, which require strict controls to protect user data and prevent unauthorized access.
However, the provided information does not explicitly detail the compliance implications or specific regulatory impacts of this vulnerability.