---
id: CVE-2026-73429
title: Russh is a Rust SSH client & server library
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
  Curve255…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-704
  - CWE-754
vendor: russh
product: russh
affected:
  - russh < 0.62.4
patched:
  - russh 0.62.4
published: '2026-08-12'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T21:02:22.660'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-73429'
references:
  - url: >-
      https://github.com/Eugeny/russh/commit/a7fc1eb5717264e31c3c5f7dd849b73989a08f3d
    label: security-advisories@github.com
  - url: 'https://github.com/Eugeny/russh/releases/tag/v0.62.4'
    label: security-advisories@github.com
  - url: 'https://github.com/Eugeny/russh/security/advisories/GHSA-g9hv-x236-4qp3'
    label: security-advisories@github.com
  - url: 'https://github.com/Eugeny/russh/security/advisories/GHSA-g9hv-x236-4qp3'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://github.com/Eugeny/russh'
tags:
  - nvd
  - osv
  - rust
epss: 0.00507
epssPercentile: 0.40622
aliases:
  - GHSA-g9hv-x236-4qp3
ecosystem: rust
ingestedAt: '2026-08-13T19:18:22.091Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-73429)

Affected packages:

- `russh < 0.62.4`

Patched in:

- `russh 0.62.4`

Source: https://osv.dev/vulnerability/GHSA-g9hv-x236-4qp3