py-treq -- sensitive information leak vulnerability

Treq’s request methods (treq.get, treq.post, HTTPClient.request, HTTPClient.get, etc.) accept cookies as a dictionary.
Such cookies are not bound to a single domain, and are therefore sent to every domain (“supercookies”).
This can potentially cause sensitive information to leak upon an HTTP redirect to a different domain., e.g. should https://example.com redirect to http://cloudstorageprovider.com the latter will receive the cookie session.