Use of Hard-coded Cryptographic Key Affecting arcade-mcp package, versions [,1.5.6)
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
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 applications- Snyk IDSNYK-PYTHON-ARCADEMCP-14171923
- published3 Dec 2025
- disclosed2 Dec 2025
- creditQi Deng
Introduced: 2 Dec 2025
CVE-2025-66454 (opens in a new tab)How to fix?
Upgrade arcade-mcp to version 1.5.6 or higher.
Overview
arcade-mcp is an Arcade.dev - Tool Calling platform for Agents
Affected versions of this package are vulnerable to Use of Hard-coded Cryptographic Key via the HTTP server uses a hardcoded default worker secret ("dev") that is never validated or overridden during normal server startup. An attacker can gain unauthorized access to all HTTP worker endpoints by forging valid JWTs using the known default secret.