CVE-2026-9798
Keycloak: keycloak: brute-force protection bypass in ciba flow
- State
- Published
- Severity
- 4.3 Medium
- Published
- May 28, 2026
- Updated
- Aug 20, 2026
- Reserved
- May 28, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 4.3 Medium | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N | redhat |
Weaknesses
- CWE-305 Authentication Bypass by Primary Weakness
Affected Products
| Product | Versions |
|---|---|
Red Hat build of Keycloak 26.4Red Hat |
|
Red Hat build of Keycloak 26.4Red Hat |
|
Red Hat build of Keycloak 26.4Red Hat |
|
Red Hat build of Keycloak 26.4.14Red Hat | |
Red Hat build of Keycloak 26.6Red Hat |
|
Red Hat build of Keycloak 26.6Red Hat |
|
Red Hat build of Keycloak 26.6Red Hat |
|
Red Hat build of Keycloak 26.6.5Red Hat |
References
- RHSA-2026:50846vendor-advisory
- RHSA-2026:50847vendor-advisory
- RHSA-2026:50848vendor-advisory
- RHSA-2026:50849vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-9798vdb-entry
- RHBZ#2482470issue-tracking
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