Blog says Cloudflare is rewriting its proxy layer in Rust
Original title: Cloudflare is rewriting everything in Rust
The author ties the shift to 2017 Cloudbleed and says a November 18, 2025 outage came from unwrap on bad config.
A blog post argues Cloudflare has moved from C and Lua NGINX modules toward Rust proxies after the February 17, 2017 Cloudbleed memory-safety leak. It says Pingora is already in Rust, FL is being replaced by Rust-based FL2, and HTTP and TLS termination is being rewritten, while the developer platform uses Go and TypeScript. The same post recounts the November 18, 2025 outage as a panic from .unwrap() on a Result fed malformed configuration, then promotes the author's Rust book.
Unconfirmed: Claims about leadership motives and the scale of the rewrite are the author's interpretation.
- Cloudbleed leaked request data, including cookies, API keys, and tokens, across sites.
- wirefilter is described as one Rust library shared by the proxy and the Go API.
- The outage post-mortem was published in under 24 hours and signed by the CEO.
- The author says many Cloudflare GitHub repos are mirrors of internal repositories.
- Products
- PingoraNGINXwirefilterFL2
- Organizations
- Cloudflare
From the original article
7 min read at kerkour.comOn February 17, 2017, a security researcher at Google found that Cloudflare reverse proxies were leaking HTTP requests traversing their network, the famous CloudBleed vulnerability. For example, let's say that you were visiting https://example. com, hosted on Cloudflare, the HTTP response served by Cloudflare may have contained HTML content or HTTP headers for completely unrelated websites also hosted on Cloudflare.
By tonyedgecombe · kerkour.com
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