CVE-2026-16103: medium-severity vulnerability in Red Hat Build of Keycloak
Keycloak-services: keycloak-services: incomplete fix for ciba brute-force lockout bypass at token redemption
Published · Updated
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 4.3epss 0.3%
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
Affected products
Red Hat · Red Hat Build of KeycloakRed Hat · Red Hat Data Grid 8Red Hat · Red Hat JBoss Enterprise Application Platform Expansion PackRed Hat · Red Hat Single Sign-On 7Related CVEs — Red Hat Build of Keycloak
In the same product, most dangerous first.
CVE-2026-18963CRITICALKeycloak-services: keycloak-services: unauthenticated account takeover via reset-credentials flow bypassEPSS 4.7%CVE-2024-1635HIGHUndertow: out-of-memory error after several closed connections with wildfly-http-client protocolEPSS 4.6%CVE-2023-5685HIGHXnio: stackoverflowexception when the chain of notifier states becomes problematically bigEPSS 3.5%CVE-2024-3656HIGHKeycloak: unguarded admin rest api endpoints allows low privilege users to use administrative functionalitiesEPSS 3.3%CVE-2024-5971HIGHUndertow: response write hangs in case of java 17 tlsv1.3 newsessionticketEPSS 2.9%CVE-2023-3223HIGHUndertow: outofmemoryerror due to @multipartconfig handlingEPSS 2.7%