Disclosure summary
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.
Source-reported weakness categories
CWE-327
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
GitHub Reviewed Security Advisories · GHSA-w3jg-pjxf-73p4
Open original source · Updated Sep 30, 2026
Russh: Missing X25519 zero-point validation in hybrid ML-KEM key exchange
Source severity: MEDIUM / 0
| Ecosystem | Package | Affected range | First patched |
|---|---|---|---|
| rust | russh | < 0.63.0 | 0.63.0 |
NIST National Vulnerability Database · NVD-CVE-2026-102824
Open original source · Updated Sep 30, 2026
Only CPE matches marked vulnerable=true are indexed. AND/OR platform conditions must be checked in the original NVD record.
Original records & references
PUBLISHED 2026-09-29T15:17:24-04:00
MODIFIED 2026-09-30T17:17:05-04:00
INGESTED 2026-10-06T11:43:05-04:00