CVE-2026-73568

{
  "id": "CVE-2026-73568",
  "sourceIdentifier": "[email protected]",
  "published": "2026-08-13T18:18:19.547",
  "lastModified": "2026-10-24T15:10:00.190",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "py-libp2p is the Python implementation of the libp2p networking stack. In 0.7.0 and earlier, the yamux handle_incoming() method in libp2p/stream_muxer/yamux/yamux.py reads an attacker-controlled 32-bit DATA frame length with read_exactly() before validating it against MAX_WINDOW_SIZE or checking whether stream_id exists. A peer that completes the standard Noise handshake can send a 12-byte frame declaring a 0xFFFFFFFF body and then withhold the body, causing the sequential yamux read loop used by the default new_host() configuration to block and preventing every stream on that connection from making progress. No fixed version is available as of this review."
    },
    {
      "lang": "es",
      "value": "py-libp2p es la implementación en Python de la pila de red libp2p. En la versión 0.7.0 y anteriores, el método yamux handle_incoming() en libp2p/stream_muxer/yamux/yamux.py lee una longitud de trama DATA de 32 bits controlada por el atacante con read_exactly() antes de validarla contra MAX_WINDOW_SIZE o de comprobar si stream_id existe. Un par que completa el handshake Noise estándar puede enviar una trama de 12 bytes declarando un cuerpo 0xFFFFFFFF y luego retener el cuerpo, lo que hace que el bucle de lectura secuencial de yamux utilizado por la configuración predeterminada de new_host() se bloquee e impida que cada flujo en esa conexión avance. No hay una versión corregida disponible a partir de esta revisión."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "libp2p",
          "product": "py-libp2p",
          "versions": [
            {
              "version": "<= 0.7.0",
              "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:H",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-08-13T18:06:28.668080Z",
          "id": "CVE-2026-73568",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-400"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/libp2p/py-libp2p/commit/146ea87d1a20cc7dacf684ecf7c204543be04b37",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/libp2p/py-libp2p/security/advisories/GHSA-hmj8-5xmh-5573",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/libp2p/py-libp2p/security/advisories/GHSA-hmj8-5xmh-5573",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ]
}