FKIE_CVE-2026-52870

Vulnerability from fkie_nvd - Published: 2026-07-15 20:17 - Updated: 2026-10-24 21:10
Severity
7.6 (High) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L
Summary
The MCP Python SDK, called mcp on PyPI, is a Python implementation of the Model Context Protocol (MCP). From 1.23.0 until 1.27.2, default handlers installed by server.experimental.enable_tasks() for tasks/list, tasks/get, tasks/result, and tasks/cancel operate only on task identifiers without recording the session that created each task, allowing any connected client to enumerate, read results from, consume messages for, or cancel other clients' tasks. This issue is fixed in version 1.27.2.
References
security-advisories@github.comhttps://github.com/modelcontextprotocol/python-sdk/commit/62137874ff26dd74d2fea80ff528a7fd9ca7a5e7Patch
security-advisories@github.comhttps://github.com/modelcontextprotocol/python-sdk/pull/2720Issue Tracking, Patch
security-advisories@github.comhttps://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.27.2Release Notes
security-advisories@github.comhttps://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-hvrp-rf83-w775Vendor Advisory
Impacted products
Vendor Product Version
lfprojects mcp_python_sdk *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "python-sdk",
          "vendor": "modelcontextprotocol",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 1.23.0, \u003c 1.27.2"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:lfprojects:mcp_python_sdk:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "788DA6BA-F84C-4AFA-B31F-7096732011C8",
              "versionEndExcluding": "1.27.2",
              "versionStartIncluding": "1.23.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The MCP Python SDK, called mcp on PyPI, is a Python implementation of the Model Context Protocol (MCP). From 1.23.0 until 1.27.2, default handlers installed by server.experimental.enable_tasks() for tasks/list, tasks/get, tasks/result, and tasks/cancel operate only on task identifiers without recording the session that created each task, allowing any connected client to enumerate, read results from, consume messages for, or cancel other clients\u0027 tasks. This issue is fixed in version 1.27.2."
    },
    {
      "lang": "es",
      "value": "El SDK de Python de MCP, llamado \u2019mcp\u2019 en PyPI, es una implementaci\u00f3n en Python del Protocolo de Contexto de Modelo (MCP). Desde la versi\u00f3n 1.23.0 hasta la 1.27.2, los manejadores predeterminados instalados por server.experimental.enable_tasks() para tasks/list, tasks/get, tasks/result y tasks/cancel operan solo en identificadores de tarea sin registrar la sesi\u00f3n que cre\u00f3 cada tarea, permitiendo a cualquier cliente conectado enumerar, leer resultados de, consumir mensajes para, o cancelar las tareas de otros clientes. Este problema est\u00e1 solucionado en la versi\u00f3n 1.27.2."
    }
  ],
  "id": "CVE-2026-52870",
  "lastModified": "2026-10-24T21:10:00.130",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 7.6,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "LOW",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 4.7,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-52870",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-07-16T13:01:33.294977Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-07-15T20:17:38.577",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/modelcontextprotocol/python-sdk/commit/62137874ff26dd74d2fea80ff528a7fd9ca7a5e7"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Issue Tracking",
        "Patch"
      ],
      "url": "https://github.com/modelcontextprotocol/python-sdk/pull/2720"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Release Notes"
      ],
      "url": "https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.27.2"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-hvrp-rf83-w775"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-862"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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