The HttpClient from Reactor Netty, versions 0.9.x prior to 0.9.5, and versions 0.8.x prior to 0.8.16, may be used incorrectly, leading to a credentials leak during a redirect to a different domain. In order for this to happen, the HttpClient must have been explicitly configured to follow redirects.

Pivotal Reactor Netty, versions prior to 0.8.11, passes headers through redirects, including authorization ones. A remote unauthenticated malicious user may gain access to credentials for a different server than they have access to.