CVE-2026-116685
mediumThe Model Context Protocol Python SDK is the official Python SDK for Model Context Protocol servers and clients.
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.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://github.com/modelcontextprotocol/python-sdk/commit/2106335745563b2321b8c73fef2c1290... security-advisories@github.com
- https://github.com/modelcontextprotocol/python-sdk/commit/c6762e821c527925f0b617db216d00fb... security-advisories@github.com
- https://github.com/modelcontextprotocol/python-sdk/pull/3397 security-advisories@github.com
- https://github.com/modelcontextprotocol/python-sdk/pull/3448 security-advisories@github.com
- https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.30.0 security-advisories@github.com
- https://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.2.0 security-advisories@github.com
- https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-5h93-6whr-6q8j security-advisories@github.com