Model Context Protocol Python SDK: HTTP Client Transports Followed Cross-origin Redirects Carrying Custom Headers And Bo

Summary In affected versions, the SDK's Streamable HTTP and SSE client transports followed HTTP redirects to any host. If the configured MCP endpoint answered with a redirect to a different origin: - custom headers set on the client for example an "X-API-Key" credential were sent to that origin,...

Model Context Protocol Python SDK: HTTP client transports followed cross-origin redirects carrying custom headers and bodies

Summary In affected versions, the SDK's Streamable HTTP and SSE client transports followed HTTP redirects to any host. If the configured MCP endpoint answered with a redirect to a different origin: - custom headers set on the client for example an X-API-Key credential were sent to that origin, an...

GHSA-5H93-6WHR-6Q8J Model Context Protocol Python SDK: HTTP client transports followed cross-origin redirects carrying custom headers and bodies

Summary In affected versions, the SDK's Streamable HTTP and SSE client transports followed HTTP redirects to any host. If the configured MCP endpoint answered with a redirect to a different origin: - custom headers set on the client for example an X-API-Key credential were sent to that origin, an...

CVE-2026-116685

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, streamablehttpclient, streamablehttpclient, sseclient, ClientSessionGroup, OAuth, and createmcphttpclient client paths enable followredirects and...

CVE-2026-116685

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, streamablehttpclient, streamablehttpclient, sseclient, ClientSessionGroup, OAuth, and createmcphttpclient client paths enable followredirects and...

EUVD-2026-111367

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, streamablehttpclient, streamablehttpclient, sseclient, ClientSessionGroup, OAuth, and createmcphttpclient client paths enable followredirects and...

Model Context Protocol MCP Python SDK information disclosure vulnerability

Versions 1.8.0 through 1.30.0 and 2.0.0 through 2.2.0 of the Model Context Protocol MCP Python SDK contain an information disclosure vulnerability. This vulnerability arises because the streamablehttpclient, streamablehttpclient, SSEclient, ClientSessionGroup, OAuth, and createmcphttpclient clien...