CVE-2025-66454

MEDIUM

arcade-mcp < 1.5.4 - Unauthenticated Authentication Bypass via Hardcoded Worker Secret

Title source: llm
STIX 2.1

Description

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.

References (3)

Core 3

Scores

CVSS v3 6.5
EPSS 0.0027
EPSS Percentile 18.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact partial

Details

CWE
CWE-321 CWE-798
Status published
Products (2)
ArcadeAI/arcade-mcp < 1.5.4
pypi/arcade-mcp-server 0 - 1.9.1PyPI
Published Dec 02, 2025
Tracked Since Feb 18, 2026