Tornado
Tornado is a Python web framework and asynchronous networking library originally developed at FriendFeed. By using non-blocking network I/O Tornado can scale to tens of thousands of open connections making it ideal for long polling WebSockets and other applications that require a long-lived connection to each user.
Official Site:
https://www.tornadoweb.org/Severity Summary:
Reference
Title
Severity
Tornado Inconsistent Interpretation of HTTP Requests (HTTP Request Smuggling) Vulnerability