CVE-2026-116684

{
  "id": "CVE-2026-116684",
  "sourceIdentifier": "[email protected]",
  "published": "2026-10-27T20:17:13.307",
  "lastModified": "2026-10-28T15:21:31.673",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The Model Context Protocol Python SDK is the official Python SDK for Model Context Protocol servers and clients. From 1.10.0 until 1.30.0 and 2.2.0, server-side bearer authentication configured through AuthSettings with token_verifier accepts a valid token issued for another service when the authorization server serves multiple resources and the TokenVerifier does not independently validate the aud audience. This resource-confusion flaw lets a token holder authenticate to the wrong MCP server and exercise that token's resulting access. This issue is fixed in versions 1.30.0 and 2.2.0."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "modelcontextprotocol",
          "product": "python-sdk",
          "versions": [
            {
              "version": ">= 1.10.0, < 1.30.0",
              "status": "affected"
            },
            {
              "version": ">= 2.0.0, < 2.2.0",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N",
          "baseScore": 6.8,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 5.2
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-863"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/modelcontextprotocol/python-sdk/commit/0c9136841ff092987a20700ff9c2c9789bda2f40",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/modelcontextprotocol/python-sdk/commit/8c2fa6eabacde869d75568e33b9d466b58c2f512",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/modelcontextprotocol/python-sdk/pull/3447",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/modelcontextprotocol/python-sdk/pull/3451",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.30.0",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.2.0",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-w4fh-qvv9-3v23",
      "source": "[email protected]"
    }
  ]
}