CVE-2026-47737 Puma PROXY Protocol v1 Accepts Repeated Protocol Headers on Persistent Connections

Puma is a Ruby/Rack web server built for parallelism. From 5.5.0 until 7.2.1 and 8.0.2, Puma is vulnerable to source IP spoofing when setremoteaddress proxyprotocol: :v1 is enabled and persistent connections are used because Puma incorrectly re-parses PROXY protocol headers after each keep-alive...