src/main/java/org/keycloak/protocol/cas/endpoints/AuthorizationEndpoint.java

@@ -76,7 +76,7 @@
            throw new ErrorPageException(session, Response.Status.BAD_REQUEST, Messages.MISSING_PARAMETER, CASLoginProtocol.SERVICE_PARAM);
        }

        client = realm.getClients().stream()
        client = realm.getClientsStream()
                .filter(c -> CASLoginProtocol.LOGIN_PROTOCOL.equals(c.getProtocol()))
                .filter(c -> RedirectUtils.verifyRedirectUri(session, service, c) != null)
                .findFirst().orElse(null);