CVE-2026-52870

Severity CVSS v4.0:

Pending analysis

Type:

Unavailable / Other

Publication date:

15/07/2026

Last modified:

16/07/2026

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&#39; tasks. This issue is fixed in version 1.27.2.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L CVSS v3.1 Severity and Metrics:

Base Score: 7.60 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): Low
Availability (A): Low

Base Score 3.x

7.60

Severity 3.x

HIGH

CVE-2026-52870

Description

Impact

References to Advisories, Solutions, and Tools