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.
Advisories
| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-5xvq-cp9x-6p6r | Russh: Pre-auth remote panic via all-zero Curve25519 peer public value (encode_mpint OOB) |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Wed, 12 Aug 2026 23:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Eugeny
Eugeny russh |
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| Vendors & Products |
Eugeny
Eugeny russh |
Wed, 12 Aug 2026 21:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | Russh: Pre-auth remote panic via all-zero Curve25519 peer public value (encode_mpint OOB) | |
| Weaknesses | CWE-754 | |
| References |
| |
| Metrics |
cvssV3_1
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Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-08-12T20:55:38.202Z
Reserved: 2026-08-12T14:32:11.796Z
Link: CVE-2026-73430
No data.
Status : Received
Published: 2026-08-12T21:17:41.883
Modified: 2026-08-12T21:17:41.883
Link: CVE-2026-73430
No data.
OpenCVE Enrichment
Updated: 2026-08-12T23:00:05Z
Weaknesses
Github GHSA