so the leaked HTTP_X_AUTH_TOKEN value is the one in provided in curl command (i assume the description is using curl command and request object that aren't related)... it is not the admin_token defined in [filter:authtoken] configuration
you are correct that the leak happens only if notifier middleware is used after auth_token middleware (which it usually is)... by default the notifier middleware is not enabled in any service.
so the leaked HTTP_X_AUTH_TOKEN value is the one in provided in curl command (i assume the description is using curl command and request object that aren't related)... it is not the admin_token defined in [filter:authtoken] configuration
you are correct that the leak happens only if notifier middleware is used after auth_token middleware (which it usually is)... by default the notifier middleware is not enabled in any service.