CVE-2026-52732

{
  "id": "CVE-2026-52732",
  "sourceIdentifier": "[email protected]",
  "published": "2026-08-18T20:17:16.710",
  "lastModified": "2026-10-22T22:10:00.250",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5.0, one unauthenticated P2P peer can monopolize all 25 MAX_INBOUND_CONCURRENCY slots in Zebra's inbound mempool download and verification pipeline. In zebrad/src/components/mempool/downloads.rs, the bounded queue was shared globally without per-peer accounting, while peer identity was not carried through Gossip and FullQueue responses were mapped to Response::Nil instead of reaching overload disconnection handling. An attacker can advertise fake transaction identifiers and remain silent so each task holds a slot until TRANSACTION_DOWNLOAD_TIMEOUT, then periodically refill the queue as slots expire. While saturated, honest peer transactions and local sendrawtransaction requests are rejected with MempoolError::FullQueue, although block validation and synchronization continue. This issue is fixed in version 4.5.0."
    },
    {
      "lang": "es",
      "value": "ZEBRA es un nodo Zcash escrito completamente en Rust. Antes de la versión 4.5.0, un par P2P no autenticado puede monopolizar las 25 ranuras MAX_INBOUND_CONCURRENCY en la tubería de descarga y verificación de la mempool entrante de Zebra. En zebrad/src/components/mempool/downloads.rs, la cola limitada se compartía globalmente sin contabilidad por par, mientras que la identidad del par no se transmitía a través de Gossip y las respuestas FullQueue se mapeaban a Response::Nil en lugar de alcanzar el manejo de desconexión por sobrecarga. Un atacante puede anunciar identificadores de transacción falsos y permanecer en silencio para que cada tarea retenga una ranura hasta TRANSACTION_DOWNLOAD_TIMEOUT, luego rellenar periódicamente la cola a medida que las ranuras expiran. Mientras está saturado, las transacciones de pares honestos y las solicitudes locales de sendrawtransaction son rechazadas con MempoolError::FullQueue, aunque la validación y sincronización de bloques continúan. Este problema está solucionado en la versión 4.5.0."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "ZcashFoundation",
          "product": "zebra",
          "versions": [
            {
              "version": "< 4.5.0",
              "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: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": "2026-08-18T19:32:12.651849Z",
          "id": "CVE-2026-52732",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-770"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/ZcashFoundation/zebra/commit/1440b43ca7df59aca948090d45117557b217a6cd",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/ZcashFoundation/zebra/releases/tag/v4.5.0",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-4fc2-h7jh-287c",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-4fc2-h7jh-287c",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ]
}