CVE-2025-53365 — MCP Python SDK has Unhandled Exception in Streamable HTTP Transport ,Leading to Denial of Service
The MCP Python SDK, called `mcp` on PyPI, is a Python implementation of the Model Context Protocol (MCP). Prior to version 1.10.0, if a client deliberately triggers an exception…
Published: 2025-07-04 · CVSS: 8.7 · CVSS 4.0
The MCP Python SDK, called `mcp` on PyPI, is a Python implementation of the Model Context Protocol (MCP). Prior to version 1.10.0, if a client deliberately triggers an exception after establishing a streamable HTTP session, this can lead to an uncaught ClosedResourceError on the server side, causing the server to crash and requiring a restart to restore service. Impact may vary depending on the deployment conditions, and presence of infrastructure-level resilience measures. Version 1.10.0 contains a patch for the issue.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7