Plug.Cowboy vulnerable to unauthenticated remote DoS via HTTP/2 `:scheme` atom-table exhaustion

Summary An unauthenticated remote denial-of-service vulnerability in Plug.Cowboy.Conn allows any attacker who can reach an HTTPS Plug.Cowboy listener via HTTP/2 to permanently exhaust the BEAM atom table and crash the entire Erlang VM. Am I Affected? All users running plugcowboy with HTTP/2 may b...