CVE-2026-46705 russh server userauth state is not reset when authentication principal changes

Russh is a Rust SSH client & server library. From version 0.34.0-beta.1 to before version 0.61.0, the russh server authentication path keeps internal userauth state across SSHMSGUSERAUTHREQUEST messages without separating that state when the request principal changes. RFC 4252 allows the user nam...