Interesting, it's worth noting that the scheme can sometimes also be used to cause SSRF to a different protocol which might not use http, like ftp or gopher, s3

Interesting, it's worth noting that the scheme can sometimes also be used to cause SSRF to a different protocol which might not use http, like ftp or gopher, s3,... SSRF are fun, sometimes the leak credentials directly also - when server is based on a trusted subsystem the auth headers might leak outside.