8.7

CVE-2025-53365: modelcontextprotocol python-sdk Uncaught Exception

CVSS: 8.7v4.0HighDeferred
AliasesGHSA-j975-95f5-7wqhPYSEC-2026-1618
Published 04-07-2025Last modified 08-07-2025
Open JSON

Vulnerability summary

CVE-2025-53365 is a high (CVSS 8.7) Uncaught Exception vulnerability in modelcontextprotocol python-sdk. EPSS estimates a 0.42% chance of exploitation in the next 30 days, higher than 34.8% of scored vulnerabilities.

Overall risk
35/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.7/10
010
High · v4.0 (CVE.org)
EPSS score
0.42%
0%100%
Low · +0.05 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 04-07-2025
    PublishedVulnerability first disclosed.
  2. 08-07-2025
    Last modifiedVulnerability information updated.

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.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.42%

Chance of exploitation in the next 30 days

Percentile

35%

Versus all other CVEs

30-day change

+0.05 pp

From 0.37% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.42%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Modelcontextprotocol1 product
PyPI1 product
  • mcp< 1.10.0

2 vendors · 2 products

References

9 links