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CVE-2026-46705

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

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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 SSH_MSG_USERAUTH_REQUEST messages without separating that state when the request principal changes. RFC 4252 allows the user name and service name fields to change between authentication requests. The issue is not that such changes are invalid. The issue is that russh-owned authentication state, such as remaining methods, partial-success state, and in-progress method state, can remain associated with the connection and then influence a later request for a different (user, service). This is an internal library state mismatch. This issue has been patched in version 0.61.0.

CVSS 5.3 · Medium · EPSS 0.2% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • russh

    Versions
    • >= 0.34.0-beta.1, < 0.61.0: Affected

    No fix published

  • rust-russh Debian:14

    Versions
    • 0.57.1-1
    • 0.57.1-2
    Affected ranges
    • ECOSYSTEM: < 0.64.1-1

    Update to 0.64.1-1

Original sources

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