CVE-2026-116685
MEDIUM
MEDIUM
Priority: 0.02
BB Relevance:
62/100
Published: 2026-10-27
Modified: 2026-10-28
First seen: 2026-10-29
Status: active
Attack Surface
Network
No Auth
No Interaction
Conf. Impact
CVSS Vector Breakdown
AV:
Network
AC:
High
PR:
None
UI:
None
S:
Unchanged
C:
High
I:
None
A:
None
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.