CVE-2026-73429
Russh: client wrong-length X25519 `clone_from_slice` panic (pre-auth DoS)
MEDIUM 5.3EPSS 0.5%
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
- Eugeny · russh
- CVSS v3.1 GITHUB
- 5.3 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - EPSS
- 0.51% chance of exploitation in the next 30 days, 42nd percentile
- Published
- 2026-08-12
- Updated
- 2026-08-14