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CVE-2026-116685 Details

ANALYZED

This CVE record has been analyzed and enriched by NVDAPI.com as an independent party.

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.

Metrics

CVSS 3.x Severity and Vector Strings:

VolerionCVSS-B:5.9 MEDIUMVector:CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

CNA: [email protected]CVSS-B:5.9 MEDIUMVector:CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

References to Advisories, Solutions, and Tools

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URL	Source(s)	Tag(s)
https://github.com/modelcontextprotocol/python-sdk/commit/2106335745563b2321b8c73fef2c12903d00aa6e	[email protected]	Source CodeVendor
https://github.com/modelcontextprotocol/python-sdk/commit/c6762e821c527925f0b617db216d00fbd1d0bf99	[email protected]	Source CodeVendor
https://github.com/modelcontextprotocol/python-sdk/pull/3397	[email protected]	Issue TrackingVendor
https://github.com/modelcontextprotocol/python-sdk/pull/3448	[email protected]	Issue TrackingVendor
https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.30.0	[email protected]	Release NotesVendor
https://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.2.0	[email protected]	Release NotesVendor
https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-5h93-6whr-6q8j	[email protected]	AdvisoryRemedyVendor

see all 7 references

Weakness Enumeration

CWE-ID	CWE Name	Source
CWE-200	Exposure of Sensitive Information to an Unauthorized Actor	[email protected]

Affected Products

Product	Versions
Model Context Protocol Python SDK	>= 1.8.0, < 1.30.0 (semver) >= 2.0.0, < 2.2.0 (semver)
CPE No CPEs found in CPE dictionary for this product. Remediation Upgrade: 1.30.0moderate effort Upgrade: 2.2.0moderate effort Workaround:low effort Supply your own HTTP client with `follow_redirects` left at `False` (`http_client=` on `streamable_http_client`; `httpx_client_factory=` on `sse_client` and `streamablehttp_client`; `ClientSessionGroup` has no such parameter).

Change History

2 change records found show changes

Date	Action	Recorded By
Oct 30, 2026	CVE Modified	CISA-ADP
Oct 27, 2026	New CVE Received	[email protected]