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CVE-2026-73429GHSA-G9HV-X236-4QP3

Russh: client wrong-length X25519 `clone_from_slice` panic (pre-auth DoS)

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 0.62.4
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: poc
  • Automatable: yes
  • Technical impact: partial

Summary

Russh is a Rust SSH client & server library. Prior to 0.62.4, a malicious SSH server can crash a russh client session with a malformed KEX_ECDH_REPLY containing a server ephemeral value that is not 32 bytes long. The client-side Curve25519Kex::compute_shared_secret function in russh/src/kex/curve25519.rs passes the decoded exchange.server_ephemeral value to clone_from_slice without validating its length, causing a deterministic panic before the server host key is verified. The panic terminates the spawned client session task and surfaces as a JoinError, while the embedding process normally remains running. This issue is fixed in version 0.62.4.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: poc · Automatable: yes · Technical impact: partial

  3. Record last updated

Affected versions

  • Eugeny russh

    fixed in 0.62.4

  • russhcrates.io

    fixed in 0.62.4

References 3

GitHub · Eugeny/russh