CVE-2026-73429

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.

Affected Software

VendorProductVersion RangeStatus
Eugenyrussh< 0.62.4affected

Weaknesses

  • CWE-704: CWE-704: Incorrect Type Conversion or Cast
  • CWE-754: CWE-754: Improper Check for Unusual or Exceptional Conditions

References