CVE-2026-67432

{
  "id": "CVE-2026-67432",
  "sourceIdentifier": "[email protected]",
  "published": "2026-07-29T20:17:12.277",
  "lastModified": "2026-10-24T13:10:00.147",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and clients. Prior to 0.23.0, MCP::Server::Transports::StreamableHTTPTransport in the mcp gem reads and parses an entire JSON-RPC POST body without a size limit, allowing an unauthenticated remote attacker to exhaust process memory. This issue is fixed in version 0.23.0."
    },
    {
      "lang": "es",
      "value": "MCP Ruby SDK es el SDK oficial de Ruby para servidores y clientes de Model Context Protocol. Antes de la versión 0.23.0, MCP::Server::Transports::StreamableHTTPTransport en la gema mcp lee y analiza un cuerpo POST JSON-RPC completo sin un límite de tamaño, permitiendo a un atacante remoto no autenticado agotar la memoria del proceso. Este problema está solucionado en la versión 0.23.0."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "modelcontextprotocol",
          "product": "ruby-sdk",
          "versions": [
            {
              "version": "< 0.23.0",
              "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": "2026-07-29T19:34:08.331178Z",
          "id": "CVE-2026-67432",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "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/modelcontextprotocol/ruby-sdk/commit/772e0cb1f9db69312006926eee59a7287ad50166",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/modelcontextprotocol/ruby-sdk/releases/tag/v0.23.0",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-h669-8m4g-r2hc",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-h669-8m4g-r2hc",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ]
}