EUVD-2025-36567

FastMCP vulnerable to windows command injection in FastMCP Cursor installer via servername...

GHSA-RJ5C-58RQ-J5G5 FastMCP vulnerable to windows command injection in FastMCP Cursor installer via server_name

Summary A command-injection vulnerability lets any attacker who can influence the servername field of an MCP execute arbitrary OS commands on Windows hosts that run fastmcp install cursor Details 1. generatecursordeeplinkservername, … embeds servername verbatim in a cursor://…?name= query string...

FastMCP vulnerable to windows command injection in FastMCP Cursor installer via server_name

Summary A command-injection vulnerability lets any attacker who can influence the servername field of an MCP execute arbitrary OS commands on Windows hosts that run fastmcp install cursor Details 1. generatecursordeeplinkservername, … embeds servername verbatim in a cursor://…?name= query string...

EUVD-2025-36568

FastMCP vulnerable to reflected XSS in client's callback page...

GHSA-MXXR-JV3V-6PGC FastMCP vulnerable to reflected XSS in client's callback page

Summary While setting up an oauth client, it was noticed that the callback page hosted by the client during the flow embeds user-controlled content without escaping or sanitizing it. This leads to a reflected Cross-Site-Scripting vulnerability. Details The affected code is located in...

FastMCP vulnerable to reflected XSS in client's callback page

Summary While setting up an oauth client, it was noticed that the callback page hosted by the client during the flow embeds user-controlled content without escaping or sanitizing it. This leads to a reflected Cross-Site-Scripting vulnerability. Details The affected code is located in...

Unintended Proxy or Intermediary ('Confused Deputy')

Overview fastmcp is a The fast, Pythonic way to build MCP servers and clients. Affected versions of this package are vulnerable to Unintended Proxy or Intermediary 'Confused Deputy' during the authentication with OAuth providers that don't support Dynamic Client Registration DCR. An attacker can...

EUVD-2025-36666

FastMCP Auth Integration Allows for Confused Deputy Account Takeover...

GHSA-C2JP-C369-7PVX FastMCP Auth Integration Allows for Confused Deputy Account Takeover

Summary FastMCP documentation covers the scenario where it is possible to use Entra ID or other providers for authentication. In this context, because Entra ID does not support Dynamic Client Registration DCR, the FastMCP-hosted MCP server is acting as the authorization provider, as declared in t...

FastMCP Auth Integration Allows for Confused Deputy Account Takeover

Summary FastMCP documentation covers the scenario where it is possible to use Entra ID or other providers for authentication. In this context, because Entra ID does not support Dynamic Client Registration DCR, the FastMCP-hosted MCP server is acting as the authorization provider, as declared in t...

Command Injection

Overview fastmcp is a The fast, Pythonic way to build MCP servers and clients. Affected versions of this package are vulnerable to Command Injection via the servername field. An attacker can execute arbitrary OS commands by supplying crafted input to this field during the installation process on...

CVE-2025-62801

FastMCP is the standard framework for building MCP applications. Versions prior to 2.13.0, a command-injection vulnerability lets any attacker who can influence the servername field of an MCP execute arbitrary OS commands on Windows hosts that run fastmcp install cursor. This vulnerability is fix...

CVE-2025-62800

FastMCP is the standard framework for building MCP applications. Versions prior to 2.13.0 have a reflected cross-site scripting vulnerability in the OAuth client callback page oauthcallback.py where unescaped user-controlled values are inserted into the generated HTML, allowing arbitrary JavaScri...

Cross-site Scripting (XSS)

Overview fastmcp is a The fast, Pythonic way to build MCP servers and clients. Affected versions of this package are vulnerable to Cross-site Scripting XSS via the createcallbackhtml function. An attacker can execute arbitrary JavaScript in the context of the callback server's origin by supplying...

CVE-2025-62801 FastMCP vulnerable to windows command injection in FastMCP Cursor installer via server_name

FastMCP is the standard framework for building MCP applications. Versions prior to 2.13.0, a command-injection vulnerability lets any attacker who can influence the servername field of an MCP execute arbitrary OS commands on Windows hosts that run fastmcp install cursor. This vulnerability is fix...

CVE-2025-62801 FastMCP vulnerable to windows command injection in FastMCP Cursor installer via server_name

FastMCP is the standard framework for building MCP applications. Versions prior to 2.13.0, a command-injection vulnerability lets any attacker who can influence the servername field of an MCP execute arbitrary OS commands on Windows hosts that run fastmcp install cursor. This vulnerability is fix...

CVE-2025-62801 FastMCP vulnerable to windows command injection in FastMCP Cursor installer via server_name

FastMCP is the standard framework for building MCP applications. Versions prior to 2.13.0, a command-injection vulnerability lets any attacker who can influence the servername field of an MCP execute arbitrary OS commands on Windows hosts that run fastmcp install cursor. This vulnerability is fix...

CVE-2025-62801

CVE-2025-62801 affects FastMCP prior to version 2.13.0, where a command-injection vulnerability exists in how the server_name field is processed during the MCP installer cursor flow on Windows. An attacker who can influence the server_name value can cause arbitrary OS commands to run on Windows h...

CVE-2025-62800 FastMCP vulnerable to reflected XSS in client's callback page

FastMCP is the standard framework for building MCP applications. Versions prior to 2.13.0 have a reflected cross-site scripting vulnerability in the OAuth client callback page oauthcallback.py where unescaped user-controlled values are inserted into the generated HTML, allowing arbitrary JavaScri...

CVE-2025-62800

FastMCP (Python framework for MCP apps) is affected prior to version 2.13.0 by a reflected XSS in the OAuth client callback page (oauth_callback.py). The vulnerability occurs when unescaped user-controlled values are inserted into the generated HTML, enabling arbitrary JavaScript execution in the...