CVE-2025-53366

Source
https://nvd.nist.gov/vuln/detail/CVE-2025-53366
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-53366.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2025-53366
Aliases
Published
2025-07-04T22:15:22Z
Modified
2025-07-08T17:01:37.302989Z
Summary
[none]
Details

The MCP Python SDK, called mcp on PyPI, is a Python implementation of the Model Context Protocol (MCP). Prior to version 1.9.4, a validation error in the MCP SDK can cause an unhandled exception when processing malformed requests, resulting in service unavailability (500 errors) until manually restarted. Impact may vary depending on the deployment conditions, and presence of infrastructure-level resilience measures. Version 1.9.4 contains a patch for the issue.

References

Affected packages

Git / github.com/modelcontextprotocol/python-sdk

Affected ranges

Type
GIT
Repo
https://github.com/modelcontextprotocol/python-sdk
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed

Affected versions

v0.*

v0.6.0
v0.8.0
v0.9.0
v0.9.1

v1.*

v1.0.0
v1.1.0
v1.1.1
v1.1.2
v1.1.3
v1.2.0
v1.2.0rc1
v1.4.0
v1.4.1
v1.5.0
v1.6.0
v1.7.0
v1.8.0
v1.8.1
v1.9.0
v1.9.1
v1.9.2
v1.9.3