oak is a middleware framework for Deno's native HTTP server, Deno Deploy, Node.js 16.5 and later, Cloudflare Workers and Bun. In versions 17.1.5 and below, it's possible to significantly slow down an oak server with specially crafted values of the x-forwarded-proto or x-forwarded-for headers.

Oak Server has ReDoS in x-forwarded-proto and x-forwarded-for headers