CVE-2026-73429: Russh is a Rust SSH client & server library

Routine

MEDIUM 5.3REMOTE

CVE-2026-73429 is a medium-severity flaw (CVSS 5.3) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 s

Why this priority

CISA SSVC: public proof of concept
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 58%)
CISA exploited list	No
Weakness	CWE-704, CWE-754
Published	2026-08-12
Last modified	2026-10-24

Publisher (CNA): GitHub, Inc.

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-08-12 21:17 UTCPublished CVE record published
2026-10-24 15:10 UTCUpdated Record last modified

Exact fixes by distribution

Rust (Cargo) · russh · FIXED · 0.62.4 · vulnerable: <= 0.62.3 · source

Set russh >= 0.62.4 in Cargo.toml, then run: cargo update -p russh

Fedora 46 · clementine · FIXED · 1.4.2-1.fc46 · FEDORA-2026-3e748ef4d3 · source

sudo dnf upgrade --advisory=FEDORA-2026-3e748ef4d3

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-73429?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2026-73429 being exploited?

CVE-2026-73429 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-73429 affect?

CVE-2026-73429 affects affected software. Severity is medium (CVSS 5.3). 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 Curve25519K

How urgent is CVE-2026-73429?

Priority 37/100. CISA SSVC: public proof of concept; Remotely exploitable, no login, no user action

References

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