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CVE PROGRAM SOURCE RECORD5.3 Medium

CVE-2026-73429

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

Description

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 products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Eugeny russh

  • < 0.62.4affected

References