Improper Check for Unusual or Exceptional Conditions Affecting rust-russh package, versions <0.64.1-1


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.6% (47th percentile)

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  • Snyk IDSNYK-DEBIAN14-RUSTRUSSH-20941716
  • published15 Oct 2026
  • disclosed12 Aug 2026

Introduced: 12 Aug 2026

CVE-2026-73430  (opens in a new tab)
CWE-754  (opens in a new tab)

How to fix?

Upgrade Debian:14 rust-russh to version 0.64.1-1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream rust-russh package and not the rust-russh package as distributed by Debian. See How to fix? for Debian:14 relevant fixed versions and status.

Russh is a Rust SSH client & server library. Prior to 0.62.4, an unauthenticated SSH client can cause a denial of service by sending SSH_MSG_KEX_ECDH_INIT with a 32-byte all-zero Q_C value. Curve25519Kex::server_dh in russh/src/kex/curve25519.rs accepts the all-zero peer public value and computes an all-zero shared secret, after which compute_exchange_hash calls encode_mpint in russh/src/kex/mod.rs and indexes beyond the end of the input while skipping leading zero bytes. The resulting panic occurs before authentication and terminates the server key-exchange task. This issue is fixed in version 0.62.4.