Missing Authorization Affecting mcp package, versions [1.23.0,1.27.2)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applicationsSnyk Learn
Learn about Missing Authorization vulnerabilities in an interactive lesson.
Start learning- Snyk IDSNYK-PYTHON-MCP-18016319
- published19 Jul 2026
- disclosed16 Jul 2026
- creditCosmo,Dewank Pant,ShrutiLohani
Introduced: 16 Jul 2026
NewCVE-2026-52870 (opens in a new tab)How to fix?
Upgrade mcp to version 1.27.2 or higher.
Overview
mcp is a Model Context Protocol SDK
Affected versions of this package are vulnerable to Missing Authorization in the default tasks/list, tasks/get, tasks/result, and tasks/cancel handlers installed by server.experimental.enable_tasks(), which act on a task by its identifier without checking which session created it. A client connected to the server can enumerate, read the results and queued messages of, and cancel tasks belonging to other clients by referencing their task identifiers.