CVE-2026-9798 Details
Description
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.
A vulnerability exists in Keycloak, an open-source identity and access management solution, allowing an attacker with valid client credentials to bypass brute-force protection on locked user accounts. This exploitation occurs within the Client-Initiated Backchannel Authentication (CIBA) flow, enabling continued authentication attempts and token issuance, potentially leading to unauthorized access. The issue arises when an account is temporarily locked due to repeated failed login attempts, allowing attackers to exploit the situation and bypass the intended security measures.
To address this vulnerability, ensure that Client-Initiated Backchannel Authentication (CIBA) is not enabled in Keycloak realms unless explicitly required. If CIBA is enabled, consider disabling it to prevent bypassing brute-force protection mechanisms. Consult the Keycloak documentation for instructions on managing CIBA configuration.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed May 29, 2026References to Advisories, Solutions, and Tools
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Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-305 | Authentication Bypass by Primary Weakness | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| redhat build of keycloak | All versions |
CPE
Remediation
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Change History
8 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Aug 20, 2026 | CVE Modified | [email protected] |
| Aug 5, 2026 | CVE Modified | [email protected] |
| Aug 5, 2026 | CVE Modified | [email protected] |
| Aug 5, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 3, 2026 | Initial Analysis | [email protected] |
| May 28, 2026 | New CVE Received | [email protected] |