{"id":"CVE-2026-116685","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-116685","generatedAt":"2026-10-28T02:24:19.738Z","title":"An attacker who can influence a trusted endpoint's redirect destination can receive that material.","description":"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.","published":"2026-10-27T20:17:13.000Z","lastModified":"2026-10-27T20:17:13.000Z","status":"Received","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":5.9,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"},"cwe":["CWE-200"],"affected":[],"epss":null,"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and no EPSS score yet. Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-27T20:17:13.000Z","detail":{"score":"5.9","severity":"MEDIUM","publishedAt":"2026-10-27T20:17:13.493Z"},"summary":"New CVE, medium severity (CVSS 5.9)."}],"references":[{"url":"https://github.com/modelcontextprotocol/python-sdk/commit/2106335745563b2321b8c73fef2c12903d00aa6e","source":"security-advisories@github.com"},{"url":"https://github.com/modelcontextprotocol/python-sdk/commit/c6762e821c527925f0b617db216d00fbd1d0bf99","source":"security-advisories@github.com"},{"url":"https://github.com/modelcontextprotocol/python-sdk/pull/3397","source":"security-advisories@github.com"},{"url":"https://github.com/modelcontextprotocol/python-sdk/pull/3448","source":"security-advisories@github.com"},{"url":"https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.30.0","source":"security-advisories@github.com"},{"url":"https://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.2.0","source":"security-advisories@github.com"},{"url":"https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-5h93-6whr-6q8j","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-116685","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}