Published: 06 August 2025 at 22:20 UTC Updated: 17 October 2025 at 10:13 UTC Abstract Upstream HTTP/1.1 is inherently insecure and regularly exposes millions of websites to hostile takeover. Six years of attempted mitigations have hidden the issue, but failed to fix it. This paper introduces several novel classes of HTTP desync attack capable of mass compromise of user credentials. These technique

