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CVE-2025-66454

CVE-2025-66454 · Arcade MCP Default Hardcoded Worker Secret Allows Full Unauthorized Access to All HTTP MCP Worker Endpoints

This page contains facts from public vulnerability sources. Check the original advisory before updating.

Arcade MCP allows you to to create, deploy, and share MCP Servers. Prior to 1.5.4, the arcade-mcp HTTP server uses a hardcoded default worker secret ("dev") that is never validated or overridden during normal server startup. As a result, any unauthenticated attacker who knows this default key can forge valid JWTs and fully bypass the FastAPI authentication layer. This grants remote access to all worker endpoints—including tool enumeration and tool invocation—without credentials. This vulnerability is fixed in 1.5.4.

CVSS 6.5 · Medium · EPSS 0.3% · Fix available

Published
Updated

Stack: python

Affected products and versions

  • arcade-mcp

    Versions
    • < 1.5.4: Affected

    No fix published

  • arcade-mcp-server PyPI

    Versions
    • 1.0.0
    • 1.0.0rc1
    • 1.0.0rc2
    • 1.0.0rc3
    • 1.0.1
    • 1.1.0
    • 1.1.1
    • 1.2.0
    • 1.2.1
    • 1.3.0
    • 1.3.1
    • 1.3.2
    • 1.4.0
    • 1.4.1
    • 1.5.0
    • 1.6.0
    • 1.6.1
    • 1.7.0
    • 1.7.1
    • 1.7.2
    • 1.7.3
    • 1.8.0
    Affected ranges
    • ECOSYSTEM: < 1.9.1

    Update to 1.9.1

Original sources

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