I'm exploring the history and evolution of the HTTP protocol and I know that HTTP/0.9 is generally not used anymore. It's clear how features evolved in newer HTTP versions and how primitive HTTP/0.9 actually is with no support for headers, no status codes, only GET method, no HTTP version declaration et cetera.
While there isn't an official "end-of-life" declaration for HTTP versions I was wondering if there are version specific security vulnerabilities or risks associated with the use of HTTP/0.9, effectively making it "end-of-life" from a security standpoint.
Related is this article from 2018, interestingly the domain still supports HTTP/0.9 as of October 2023, tested using telnet: https://www.tobymackenzie.com/blog/2018/02/18/supporting-http-0-9/.