CVE-2026-47427

{
  "id": "CVE-2026-47427",
  "sourceIdentifier": "[email protected]",
  "published": "2026-07-28T16:18:14.853",
  "lastModified": "2026-10-24T13:10:00.147",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "GitHub MCP Server is GitHub's official MCP Server. Prior to 1.1.0, the CompletionsHandler function in pkg/github/server.go accesses params.Ref without first checking whether it is nil, so a completion/complete request with a missing or empty ref field triggers a nil pointer dereference and a Go runtime panic; because the crash occurs before any authentication or token validation, any unauthenticated client able to send JSON-RPC messages can crash the server, resulting in a complete denial of service. This issue is fixed in version 1.1.0."
    },
    {
      "lang": "es",
      "value": "El Servidor MCP de GitHub es el Servidor MCP oficial de GitHub. Antes de la 1.1.0, la función CompletionsHandler en pkg/github/server.go accede a params.Ref sin verificar primero si es nulo, por lo que una solicitud de completion/complete con un campo ref faltante o vacío desencadena una desreferenciación de puntero nulo y un pánico en tiempo de ejecución de Go; debido a que el fallo ocurre antes de cualquier autenticación o validación de token, cualquier cliente no autenticado capaz de enviar mensajes JSON-RPC puede hacer que el servidor falle, resultando en una denegación de servicio completa. Este problema está solucionado en la versión 1.1.0."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "github",
          "product": "github-mcp-server",
          "versions": [
            {
              "version": "< 1.1.0",
              "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": "2026-07-28T17:31:12.371732Z",
          "id": "CVE-2026-47427",
          "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-476"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:github:mcp_server:*:*:*:*:*:*:*:*",
              "versionEndExcluding": "1.1.0",
              "matchCriteriaId": "FEBF9CB4-D9DD-4A31-B17E-F5B42B16AEE1"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/github/github-mcp-server/commit/c88d2ecdd3bb07f7bdd75296e3ee676febf14f58",
      "source": "[email protected]",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://github.com/github/github-mcp-server/pull/2502",
      "source": "[email protected]",
      "tags": [
        "Issue Tracking",
        "Patch"
      ]
    },
    {
      "url": "https://github.com/github/github-mcp-server/releases/tag/v1.1.0",
      "source": "[email protected]",
      "tags": [
        "Release Notes"
      ]
    },
    {
      "url": "https://github.com/github/github-mcp-server/security/advisories/GHSA-w4q6-qw23-4rg7",
      "source": "[email protected]",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://github.com/github/github-mcp-server/security/advisories/GHSA-w4q6-qw23-4rg7",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ]
    }
  ]
}