{"answers":{"affected":"4 open source packages ship an affected version, including mcp.","exploited":"There is no known exploitation of CVE-2026-116685 in the wild and no public exploit code.","fix":"Upgrade mcp to a fixed version for your release line: 1.30.0 or 2.2.0.","what":"CVE-2026-116685 is a medium-severity vulnerability in modelcontextprotocol python-sdk, published on 27 Oct 2026."},"fix_prompt":"Check this codebase for CVE-2026-116685 and fix it if it is affected.\n\nWhat it is: CVE-2026-116685 is a medium-severity vulnerability in modelcontextprotocol python-sdk, published on 27 Oct 2026. \nExploitation: There is no known exploitation of CVE-2026-116685 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- mcp (PyPI): affected from 1.8.0; fixed in 1.30.0\n- mcp (PyPI): affected from 1.8.0; fixed in 1.30.0\n- mcp (PyPI): affected from 2.0.0; fixed in 2.2.0\n- mcp (PyPI): affected from 2.0.0; fixed in 2.2.0\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-116685/ (Markdown: https://insights.sbomify.com/CVE-2026-116685/index.md)","id":"CVE-2026-116685","markdown":"https://insights.sbomify.com/CVE-2026-116685/index.md","name":"CVE-2026-116685","record":{"aliases":["GHSA-5h93-6whr-6q8j"],"analysis":null,"analysis_generated_by":null,"assigner":"GitHub_M","cpe":[],"cvss":{"score":5.9,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","version":"3.1"},"cwes":[{"id":"CWE-200","name":"Exposure of Sensitive Information to an Unauthorized Actor"}],"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.","ecosystems":["PyPI"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"Model Context Protocol Python SDK: HTTP client transports followed cross-origin redirects carrying custom headers and bodies","id":"CVE-2026-116685","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":null,"products":[],"type":null,"year":"2026"},"n_packages":4,"n_references":7,"next":{"headline":"Model Context Protocol Python SDK: Client fetched server-chosen $ref URLs while validating tool results against output schemas","id":"CVE-2026-116686"},"packages":[{"ecosystem":"PyPI","fixed":["1.30.0"],"introduced":["1.8.0"],"last_affected":[],"package":"mcp","purl":null,"source":"GHSA-5h93-6whr-6q8j"},{"ecosystem":"PyPI","fixed":["1.30.0"],"introduced":["1.8.0"],"last_affected":[],"package":"mcp","purl":"pkg:pypi/mcp","source":"GHSA-5h93-6whr-6q8j"},{"ecosystem":"PyPI","fixed":["2.2.0"],"introduced":["2.0.0"],"last_affected":[],"package":"mcp","purl":null,"source":"GHSA-5h93-6whr-6q8j"},{"ecosystem":"PyPI","fixed":["2.2.0"],"introduced":["2.0.0"],"last_affected":[],"package":"mcp","purl":"pkg:pypi/mcp","source":"GHSA-5h93-6whr-6q8j"}],"prev":{"headline":"Model Context Protocol Python SDK: Server bearer-token authentication accepts tokens issued for a different resource server","id":"CVE-2026-116684"},"products":["python-sdk"],"published":"2026-10-27","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-10-27","vendors":["modelcontextprotocol"]},"summary":null,"url":"https://insights.sbomify.com/CVE-2026-116685/"}