A flaw was found in Keycloak. A vulnerability exists in the jwt-authorization-grant flow where the server fails to verify if an Identity Provider (IdP) is enabled before issuing tokens. The issuer lookup mechanism (lookupIdentityProviderFromIssuer) retrieves the IdP configuration but does not filter for isEnabled=false. If an administrator disables an IdP (e.g., due to a compromise or offboarding), an entity possessing that IdPs signing key can still generate valid JWT assertions that Keycloak accepts, resulting in the issuance of valid access tokens.
Weakness
The product does not implement or incorrectly implements one or more security-relevant checks as specified by the design of a standardized algorithm, protocol, or technique.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Red Hat build of Keycloak 26.4 | RedHat | rhbk/keycloak-operator-bundle:26.4.9-1 | * |
| Red Hat build of Keycloak 26.4 | RedHat | rhbk/keycloak-rhel9:26.4-11 | * |
| Red Hat build of Keycloak 26.4 | RedHat | rhbk/keycloak-rhel9-operator:26.4-10 | * |
| Red Hat build of Keycloak 26.4.9 | RedHat | rhbk/keycloak-rhel9 | * |