{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-116685",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-10-26T20:00:59.830Z",
        "datePublished": "2026-10-27T19:26:46.926Z",
        "dateUpdated": "2026-10-27T19:26:46.926Z"
    },
    "containers": {
        "cna": {
            "title": "Model Context Protocol Python SDK: HTTP client transports followed cross-origin redirects carrying custom headers and bodies",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-200",
                            "lang": "en",
                            "description": "CWE-200: Exposure of Sensitive Information to an Unauthorized Actor",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "HIGH",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "NONE",
                        "baseScore": 5.9,
                        "baseSeverity": "MEDIUM",
                        "confidentialityImpact": "HIGH",
                        "integrityImpact": "NONE",
                        "privilegesRequired": "NONE",
                        "scope": "UNCHANGED",
                        "userInteraction": "NONE",
                        "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-5h93-6whr-6q8j",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-5h93-6whr-6q8j"
                },
                {
                    "name": "https://github.com/modelcontextprotocol/python-sdk/pull/3397",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/modelcontextprotocol/python-sdk/pull/3397"
                },
                {
                    "name": "https://github.com/modelcontextprotocol/python-sdk/pull/3448",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/modelcontextprotocol/python-sdk/pull/3448"
                },
                {
                    "name": "https://github.com/modelcontextprotocol/python-sdk/commit/2106335745563b2321b8c73fef2c12903d00aa6e",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/modelcontextprotocol/python-sdk/commit/2106335745563b2321b8c73fef2c12903d00aa6e"
                },
                {
                    "name": "https://github.com/modelcontextprotocol/python-sdk/commit/c6762e821c527925f0b617db216d00fbd1d0bf99",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/modelcontextprotocol/python-sdk/commit/c6762e821c527925f0b617db216d00fbd1d0bf99"
                },
                {
                    "name": "https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.30.0",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.30.0"
                },
                {
                    "name": "https://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.2.0",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.2.0"
                }
            ],
            "affected": [
                {
                    "vendor": "modelcontextprotocol",
                    "product": "python-sdk",
                    "versions": [
                        {
                            "version": ">= 1.8.0, < 1.30.0",
                            "status": "affected"
                        },
                        {
                            "version": ">= 2.0.0, < 2.2.0",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-10-27T19:26:46.926Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "The Model Context Protocol Python SDK is the official Python SDK for Model Context Protocol servers and clients. From 1.8.0 until 1.30.0 and 2.2.0, streamable_http_client, streamablehttp_client, sse_client, ClientSessionGroup, OAuth, and create_mcp_http_client client paths enable follow_redirects and follow redirects to a different origin, forwarding caller-supplied custom credential headers and, for 307 or 308 responses, the request body. An attacker who can influence a trusted endpoint's redirect destination can receive that material. This issue is fixed in versions 1.30.0 and 2.2.0."
                }
            ],
            "source": {
                "advisory": "GHSA-5h93-6whr-6q8j",
                "discovery": "UNKNOWN"
            }
        }
    }
}