# CVE-2026-73429

## Summary

- **CVE ID:** CVE-2026-73429
- **Severity:** MEDIUM
- **CVSS Score:** 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L)
- **CWE:** CWE-704, CWE-754
- **Published:** Aug 12, 2026
- **Last Modified:** Aug 14, 2026

## 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

- Eugeny — russh (< 0.62.4)

## References

- [CNA](https://github.com/Eugeny/russh/security/advisories/GHSA-g9hv-x236-4qp3)
- [CNA](https://github.com/Eugeny/russh/commit/a7fc1eb5717264e31c3c5f7dd849b73989a08f3d)
- [CNA](https://github.com/Eugeny/russh/releases/tag/v0.62.4)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.29%
- **EPSS Percentile:** 21.5

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._