CVE-2026-34230 Rack: Quadratic complexity in Rack::Utils.select_best_encoding via wildcard Accept-Encoding header

Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Utils.selectbestencoding processes Accept-Encoding values with quadratic time complexity when the header contains many wildcard entries. Because this method is used by Rack::Deflater to choose a respon...