{"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"}}}}