CVE-2026-73430
CVE-2026-73430 · Russh: Pre-auth remote panic via all-zero Curve25519 peer public value (encode_mpint OOB)
This page contains facts from public vulnerability sources. Check the original advisory before updating.
Russh is a Rust SSH client & server library. Prior to 0.62.4, an unauthenticated SSH client can cause a denial of service by sending SSH_MSG_KEX_ECDH_INIT with a 32-byte all-zero Q_C value. Curve25519Kex::server_dh in russh/src/kex/curve25519.rs accepts the all-zero peer public value and computes an all-zero shared secret, after which compute_exchange_hash calls encode_mpint in russh/src/kex/mod.rs and indexes beyond the end of the input while skipping leading zero bytes. The resulting panic occurs before authentication and terminates the server key-exchange task. This issue is fixed in version 0.62.4.
CVSS 5.3 · Medium · EPSS 0.6% · Fix available
- Published
- Updated
Stack: system
Affected products and versions
russh
- Versions
- < 0.62.4: Affected
No fix published
rust-russh Debian:14
- Versions
- 0.57.1-1
- 0.57.1-2
- Affected ranges
- ECOSYSTEM: < 0.64.1-1
Update to 0.64.1-1
rust-russh Ubuntu:26.10
- Versions
- 0.57.1-2
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published