CVE-2025-53365

CVE-2025-53365 is a high-severity vulnerability with a CVSS 4.0 base score of 8.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-248.

Key facts

Description

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.

Frequently asked questions

What is CVE-2025-53365?
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.
How severe is CVE-2025-53365?
CVE-2025-53365 has a CVSS 4.0 base score of 8.7, rated high severity.
Is CVE-2025-53365 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-53365?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-53365 have an EU (EUVD) identifier?
Yes. CVE-2025-53365 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-20094.
When was CVE-2025-53365 published?
CVE-2025-53365 was published on 2025-07-04 and last updated on 2026-06-17.

References

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