CVE-2026-55605

{
  "id": "CVE-2026-55605",
  "sourceIdentifier": "[email protected]",
  "published": "2026-07-09T22:17:06.400",
  "lastModified": "2026-10-25T17:10:00.197",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "DeepSeek MCP Server is an MCP server for DeepSeek V4. Starting in version 1.4.2 and prior to version 1.8.0, the self-hosted HTTP transport of `@arikusi/deepseek-mcp-server` exposes `POST /mcp` without any authentication: `createMcpExpressApp` is called without an `authProvider` and no middleware guards the route, so any network-reachable client can issue an unauthenticated `initialize` request and obtain a valid MCP session identifier. In reproduced testing against commit `5e1302171e99`, an unauthenticated client was able to initialize a session, enumerate tools, and invoke the local `deepseek_sessions` tool with no credentials. The same unauthenticated session also exposes `deepseek_chat`, whose handler uses the server-side `DEEPSEEK_API_KEY` when self-hosted deployments configure one. This issue applies to self-hosted HTTP mode, not the separately documented hosted BYOK endpoint in `README.md`, which expects an `Authorization: Bearer ...` header. Upstream self-hosted container assets enable HTTP mode by default (`Dockerfile`) and publish port `3000` (`docker-compose.yml`). Version 1.8.0 contains a patch for this issue."
    },
    {
      "lang": "es",
      "value": "DeepSeek MCP Server es un servidor MCP para DeepSeek V4. A partir de la versión 1.4.2 y antes de la versión 1.8.0, el transporte HTTP autoalojado de “@arikusi/deepseek-mcp-server” expone “POST /mcp” sin ninguna autenticación: “createMcpExpressApp” se llama sin un “authProvider” y ningún middleware protege la ruta, por lo que cualquier cliente accesible por red puede emitir una solicitud “initialize” no autenticada y obtener un identificador de sesión MCP válido. En pruebas reproducidas contra el commit “5e1302171e99”, un cliente no autenticado pudo inicializar una sesión, enumerar herramientas e invocar la herramienta local “deepseek_sessions” sin credenciales. La misma sesión no autenticada también expone “deepseek_chat”, cuyo gestor utiliza la “DEEPSEEK_API_KEY” del lado del servidor cuando las implementaciones autoalojadas configuran una. Este problema se aplica al modo HTTP autoalojado, no al endpoint BYOK alojado documentado por separado en “README.md”, que espera un encabezado “Authorization: Bearer ...”. Los activos de contenedor autoalojados upstream habilitan el modo HTTP por defecto (“Dockerfile”) y publican el puerto “3000” (“docker-compose.yml”). La versión 1.8.0 contiene un parche para este problema."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "arikusi",
          "product": "deepseek-mcp-server",
          "versions": [
            {
              "version": ">= 1.4.2, < 1.8.0",
              "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": "2026-07-10T13:35:04.651716Z",
          "id": "CVE-2026-55605",
          "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-306"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/arikusi/deepseek-mcp-server/blob/main/CHANGELOG.md#180---2026-06-14",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/arikusi/deepseek-mcp-server/releases/tag/v1.8.0",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/arikusi/deepseek-mcp-server/security/advisories/GHSA-72f3-6w86-7rv3",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/arikusi/deepseek-mcp-server/security/advisories/GHSA-72f3-6w86-7rv3",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ]
}