CVE-2026-73430

{
  "id": "CVE-2026-73430",
  "sourceIdentifier": "[email protected]",
  "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": "[email protected]",
      "affectedData": [
        {
          "vendor": "Eugeny",
          "product": "russh",
          "versions": [
            {
              "version": "< 0.62.4",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "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": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-754"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/Eugeny/russh/commit/a7fc1eb5717264e31c3c5f7dd849b73989a08f3d",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/Eugeny/russh/releases/tag/v0.62.4",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/Eugeny/russh/security/advisories/GHSA-5xvq-cp9x-6p6r",
      "source": "[email protected]"
    }
  ]
}