CVE-2026-102824
Russh: Missing X25519 zero-point validation in hybrid ML-KEM key exchange
- State
- Published
- Severity
- 4.3 Medium
- Published
- Sep 29, 2026
- Updated
- Sep 30, 2026
- Reserved
- Sep 29, 2026
Description
Russh is a Rust SSH client and server library. Prior to 0.63.0, the hybrid ML-KEM 768 and X25519 implementation in russh/src/kex/hybrid_mlkem.rs accepts an all-zero 32-byte peer X25519 public key in both server_dh and compute_shared_secret, forcing the X25519 contribution to the combined shared secret to zero. A malicious SSH peer can therefore make the combined secret depend only on ML-KEM, defeating the hybrid exchange's intended fallback protection if ML-KEM is later weakened. This issue is fixed in version 0.63.0.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 4.3 Medium | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N | GitHub_M |
Weaknesses
- CWE-327 Use of a Broken or Risky Cryptographic Algorithm
Affected Products
| Product | Versions |
|---|---|
russhEugeny |
|
References
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