Medium [CVE-2026-79652] JWT Bearer authorization grant does not enforce consentRequired

A flaw was found in the JWT Bearer authorization grant implementation within the keycloak-services component of Red Hat Build of Keycloak. This component handles various OAuth2 and OpenID Connect grant types used for issuing access tokens.

The issue occurs because the JWT Bearer grant fails to check if a client requires user consent before issuing a token. This allows an authenticated attacker with valid client credentials and a trusted identity provider assertion to bypass the consent requirement and obtain unauthorized access to a user account at a consent-gated client.

The Red Hat Product Security team has assessed the severity of this vulnerability as Moderate, given that exploitation requires a specific non-default client configuration and the possession of valid client credentials and a trusted IdP assertion.

Successful exploitation allows an attacker to bypass user consent requirements and obtain an access token for a target user. The vulnerability's root cause is a missing authorization check in the JWT Bearer grant implementation that fails to honor the consentRequired configuration flag.

Weakness: CWE-862. Affected Red Hat products: Red Hat build of Keycloak 26.6; Red Hat build of Keycloak 26.6.7.

Red Hat lists Red Hat Single Sign-On 7 as not affected. Red Hat fixing advisory: RHSA-2026:68277, RHSA-2026:68278.