HTTP::Tiny versions before 0.095 for Perl forward credential headers to cross-origin redirect targets. When the server returns a 3xx redirect, "_maybe_redirect" follows the "Location:" header and "_prepare_headers_and_cb" re-merges the caller's "headers" argument into the new request, without checking whether the redirect target shares an origin with the original URL. Caller-supplied "Authorization", "Cookie" and "Proxy-Authorization" headers are therefore re-sent to whatever host the redirect names, across scheme, host or port boundaries, and including "https" to "http" downgrades that expose them in plaintext on the wire. The HTTP::Tiny POD note that "Authorization headers will not be included in a redirected request" applied only to the URL-userinfo Basic-auth path, not to headers passed explicitly by the caller.