aio-libs aiohttp-session contains a Session Fixation vulnerability in load_session function for RedisStorage (see: https://github.com/aio-libs/aiohttp-session/blob/master/aiohttp_session/redis_storage.py#L42) that can result in Session Hijacking. This attack appear to be exploitable via Any method that allows setting session cookies (?session=<>, or meta tags or script tags with Set-Cookie).