{"id":"CVE-2026-73430","sourceIdentifier":"security-advisories@github.com","published":"2026-08-12T21:17:41.883","lastModified":"2026-10-24T15:10:00.190","vulnStatus":"Deferred","cveTags":[],"descriptions":[{"lang":"en","value":"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."},{"lang":"es","value":"Russh es una biblioteca SSH de cliente y servidor de Rust. Antes de la versión 0.62.4, un cliente SSH no autenticado puede causar una denegación de servicio al enviar SSH_MSG_KEX_ECDH_INIT con un valor Q_C de 32 bytes todo ceros. Curve25519Kex::server_dh en russh/src/kex/curve25519.rs acepta el valor público del par todo ceros y calcula un secreto compartido todo ceros, después de lo cual compute_exchange_hash llama a encode_mpint en russh/src/kex/mod.rs e indexa más allá del final de la entrada mientras omite los bytes cero iniciales. El pánico resultante ocurre antes de la autenticación y termina la tarea de intercambio de claves del servidor. Este problema está solucionado en la versión 0.62.4."}],"affected":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"Eugeny","product":"russh","versions":[{"version":"< 0.62.4","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","baseScore":5.3,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"LOW"},"exploitabilityScore":3.9,"impactScore":1.4}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-08-13T17:49:19.811444Z","id":"CVE-2026-73430","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-754"}]}],"references":[{"url":"https://github.com/Eugeny/russh/commit/a7fc1eb5717264e31c3c5f7dd849b73989a08f3d","source":"security-advisories@github.com"},{"url":"https://github.com/Eugeny/russh/releases/tag/v0.62.4","source":"security-advisories@github.com"},{"url":"https://github.com/Eugeny/russh/security/advisories/GHSA-5xvq-cp9x-6p6r","source":"security-advisories@github.com"}]}