CVE-2026-52870

HIGH SEVERITY

CVSS Score & Metrics

Base Score

7.6 / 10

Vector String

                                        CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L                                    

Vulnerability Description

The MCP Python SDK, called mcp on PyPI, is a Python implementation of the Model Context Protocol (MCP). From 1.23.0 until 1.27.2, default handlers installed by server.experimental.enable_tasks() for tasks/list, tasks/get, tasks/result, and tasks/cancel operate only on task identifiers without recording the session that created each task, allowing any connected client to enumerate, read results from, consume messages for, or cancel other clients' tasks. This issue is fixed in version 1.27.2.

Vulnerability Details

Published Date

July 15, 2026

Last Modified

July 15, 2026

CWE ID

CWE-862

Source

NVD

Vendor

modelcontextprotocol

Product

python-sdk

External References

https://github.com/modelcontextprotocol/python-sdk/commit/62137874ff26dd74d2fea80ff528a7fd9ca7a5e7
https://github.com/modelcontextprotocol/python-sdk/pull/2720
https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.27.2
https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-hvrp-rf83-w775

CVE-2026-52870

CVSS Score & Metrics

Vulnerability Description

Vulnerability Details

External References

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