CVE-2026-73429: medium-severity vulnerability in Eugeny russh
Russh: client wrong-length X25519 `clone_from_slice` panic (pre-auth DoS)
Published · Updated
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Affected products
Eugeny · russhRelated CVEs — Eugeny russh
In the same product, most dangerous first.
CVE-2024-43410HIGHRussh has an OOM Denial of Service due to allocation of untrusted amountEPSS 0.9%CVE-2026-73430MEDIUMRussh: Pre-auth remote panic via all-zero Curve25519 peer public value (encode_mpint OOB)EPSS 0.6%CVE-2026-42189HIGHRussh: Pre-auth DoS via unbounded allocation in keyboard-interactive authEPSS 0.5%CVE-2026-73489MEDIUMRussh: Post-auth remote panic via pty-req with more than 130 terminal-mode recordsEPSS 0.5%CVE-2025-54804MEDIUMRussh is missing an overflow check during channel windows adjustEPSS 0.4%CVE-2026-68930MEDIUMRussh: Channel-scoped server callbacks can be reached without an open channelEPSS 0.4%