EEF-CVE-2026-113440

HTTP/1.1 and HTTP/2 redirects resend basic_auth and cookie to a different scheme or port in hackney

## Summary Insufficiently Protected Credentials vulnerability in `hackney` in benoitc hackney allows a redirecting server to obtain the `basic_auth` and `cookie` credentials of a request via a same-host redirect to another scheme or port. With `follow_redirect` enabled, `hackney:follow_redirect/10` in `src/hackney.erl` reissues the request to the `Location` target after `hackney:maybe_strip_auth_on_redirect/3`, which compared only the hostname of the current and the redirect URL. A redirect from `https` to `http` on the same host resent the `Authorization` and `Cookie` headers in cleartext, where an on-path attacker can read them, and a redirect to another port on the same host handed them to a different service. `location_trusted` forwards credentials to any target by design and is unchanged. This issue affects hackney: from 2.0.0 before 4.9.0. ## Details **1. Redirect handling.** With `follow_redirect` set, `hackney:request/5` hands a 3xx response to `hackney:follow_redirect/10` in `src/hackney.erl`, which resolves the `Location` header against the current URL and calls `hackney:request/5` again with the caller's options and an empty header list. HTTP/1.1 and HTTP/2 share this path. **2. Host-only comparison.** Before the new request, `hackney:maybe_strip_auth_on_redirect/3` removes the `basic_auth` and `cookie` options when the redirect leaves the current host, unless `location_trusted` is set. It compared `#hackney_url.host` of the two URLs. **3. Consequence.** A redirect that keeps the hostname but changes the scheme or the port passes the check, so the new request carries the same `Authorization` and `Cookie` headers. From `https` to `http` they travel in cleartext; to another port they reach a different service on the same host. ## Impact A server that answers a credentialed request with a same-host redirect to plain HTTP exposes the client's `Authorization` and `Cookie` headers to anyone on the network path, and a redirect to another port delivers them to whatever service listens there. The captured values can be replayed against the original origin. ## Workarounds Disable `follow_redirect` and handle the `Location` header in the application, or pass the credentials as explicit `Authorization` and `Cookie` request headers instead of the `basic_auth` and `cookie` options. `hackney:follow_redirect/10` issues the redirected request with an empty header list, so explicit headers reach the first server only. ## Configurations The request is made with `follow_redirect` enabled and the `basic_auth` or `cookie` option set, over HTTP/1.1 or HTTP/2, without `location_trusted`. Credentials passed as explicit request headers are not forwarded on redirects and are not affected.