CVE Catalog

CVE-2025-66454

MediumCVSS 6.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.31%

23th percentile - higher than 23% of all known CVEs

Summary

Arcade MCP prior to 1.5.4 uses a hardcoded default worker secret ("dev") that is never validated or overridden during normal server startup. As a result, an unauthenticated attacker who knows this default key can forge valid JWTs and fully bypass the FastAPI authentication layer, gaining remote access to all worker endpoints.

Risk Assessment

An unauthenticated attacker can gain full access to worker endpoints, including tool enumeration and invocation, without credentials. This could lead to unauthorized access and potential further attacks.

Recommendation

Update Arcade MCP to version 1.5.4 or later. Ensure default secrets are changed and validated during server startup.

Related vulnerabilities

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS