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CVE-2025-53365

CVE-2025-53365 · MCP Python SDK has Unhandled Exception in Streamable HTTP Transport ,Leading to Denial of Service

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 8.7 · High · EPSS 0.4% · Fix available

Published
Updated

Stack: python

Affected products and versions

  • python-sdk

    Versions
    • < 1.10.0: Affected

    No fix published

  • mcp PyPI

    Versions
    • 0.9.1
    • 1.0.0
    • 1.1.0
    • 1.1.1
    • 1.1.2
    • 1.1.3
    • 1.2.0
    • 1.2.0rc1
    • 1.2.1
    • 1.3.0
    • 1.3.0rc1
    • 1.4.0
    • 1.4.1
    • 1.5.0
    • 1.6.0
    • 1.7.0
    • 1.7.1
    • 1.8.0
    • 1.8.1
    • 1.9.0
    • 1.9.1
    • 1.9.2
    • 1.9.3
    • 1.9.4
    Affected ranges
    • ECOSYSTEM: < 1.10.0

    Update to 1.10.0

Original sources

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