CVE-2026-44487: Axios: Proxy-Authorization Credential Leak to Origin Server Across HTTP-to-HTTPS Redirect in Axios Node.js HTTP Adapter

Axios’s Node.js HTTP adapter may forward a Proxy-Authorization header to a redirected origin during specific proxy-to-direct redirect flows.

This affects Node.js usage, where an initial HTTP request is sent through an authenticated HTTP proxy, redirects are followed, and the redirected URL is no longer proxied. Under affected redirect shapes, the final origin can receive the proxy credential that was intended only for the outbound proxy.

Axios’s Node.js http adapter can incorrectly forward a retained Proxy-Authorization header to the final HTTPS origin during certain HTTP-to-HTTPS redirect flows.

When an initial HTTP request is sent through an authenticated HTTP_PROXY, and the redirected HTTPS request is sent directly because no proxy applies to the redirected HTTPS URL, Axios retains the stale Proxy-Authorization header and forwards it to the final origin.