CVE-2026-16103
Keycloak-services: keycloak-services: incomplete fix for ciba brute-force lockout bypass at token redemption
CVSS Score
4.3
EPSS Score
0.0%
EPSS Percentile
0th
A flaw was found in the keycloak-services component of Keycloak. This issue is an incomplete fix for CVE-2026-9798, where brute-force protection checks were added to the Client-Initiated Backchannel Authentication (CIBA) initiation handler but were omitted from the token redemption handler. This allows an attacker with valid client credentials to obtain access and refresh tokens for a user account that has been locked due to brute-force protection, provided the authentication request was started before the lockout occurred and was approved by the user.
| Vendor | red hat |
| Product | red hat build of keycloak |
| Published | Jul 17, 2026 |
| Last Updated | Jul 17, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None
Affected Versions
Red Hat / Red Hat Build of Keycloak
All versions affected Red Hat / Red Hat Build of Keycloak
All versions affected Red Hat / Red Hat Build of Keycloak
All versions affected Red Hat / Red Hat Data Grid 8
All versions affected Red Hat / Red Hat JBoss Enterprise Application Platform Expansion Pack
All versions affected Red Hat / Red Hat Single Sign-On 7
All versions affected References
Credits
Red Hat would like to thank johanw for reporting this issue.