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

Read the record on cve.org

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

CVSSScoreVectorSource
3.14.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:Nredhat

Weaknesses

  • CWE-305 Authentication Bypass by Primary Weakness

Affected Products

ProductVersions
Red Hat build of Keycloak 26.4Red Hat
  • 26.4.14-1 and laterNot affected
Red Hat build of Keycloak 26.4Red Hat
  • 26.4-22 and laterNot affected
Red Hat build of Keycloak 26.4Red Hat
  • 26.4-22 and laterNot affected
Red Hat build of Keycloak 26.4.14Red Hat
    Red Hat build of Keycloak 26.6Red Hat
    • 26.6.5-1 and laterNot affected
    Red Hat build of Keycloak 26.6Red Hat
    • 26.6-11 and laterNot affected
    Red Hat build of Keycloak 26.6Red Hat
    • 26.6-11 and laterNot affected
    Red Hat build of Keycloak 26.6.5Red Hat

      References

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