CVE-2026-52870

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.

CVSS v3 7.6 HIGH

7.6^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 4.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact LOW

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://github.com/modelcontextprotocol/python-sdk/commit/62137874ff26dd74d2fea80ff528a7fd9ca7a5e7	Patch
https://github.com/modelcontextprotocol/python-sdk/pull/2720	Issue Tracking Patch
https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.27.2	Release Notes
https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-hvrp-rf83-w775	Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:lfprojects:mcp_python_sdk:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-07-15 20:17

Updated : 2026-07-17 18:07

NVD link : CVE-2026-52870

Mitre link : CVE-2026-52870

CVE.ORG link : CVE-2026-52870

JSON object : View

Products Affected

lfprojects

mcp_python_sdk

CWE

CWE-862

Missing Authorization

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