Summary

Faraday::Connection#build_exclusive_url still allows protocol-relative host override when the request target is provided as a URI object instead of a String. This bypasses the February 2026 fix for GHSA-33mh-2634-fwr2 and can redirect a request built from a fixed-base Faraday::Connection to an attacker-controlled host while preserving connection-scoped headers such as Authorization.

Supporting Materials

• Existing advisory for the original string-based issue: GHSA-33mh-2634-fwr2
• Existing CVE for the original string-based issue: CVE-2026-25765
• Existing regression tests for the string-only fix:
  • spec/faraday/connection_spec.rb:314-345
• Existing test proving supported URI request input:
  • spec/faraday/request_spec.rb:26-31

Impact

The direct consequence is off-host request forgery from code paths that believe they are constrained to a fixed base URL. If the connection carries default headers or query parameters, those values are forwarded to the attacker-selected host.