Arcade MCP Default Hardcoded Worker Secret Allows Full Unauthorized Access to All HTTP MCP Worker Endpoints

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2025-66454
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2025-12-02 19:15:52 UTC
Updated2026-10-18 18:10:00 UTC
DescriptionArcade 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.

Risk And Classification

Primary CVSS: v3.1 6.5 MEDIUM from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

EPSS: 0.003130000 probability, percentile 0.226870000 (date 2026-10-18)

Problem Types: CWE-321 | CWE-798 | CWE-321 CWE-321: Use of Hard-coded Cryptographic Key | CWE-798 CWE-798: Use of Hard-coded Credentials

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary6.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
3.1CNADECLARED6.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA ArcadeAI Arcade-mcp affected < 1.5.4 Not specified

References

ReferenceSourceLinkTags
github.com/ArcadeAI/arcade-mcp/security/advisories/GHSA-g2jx-37x6-6438 [email protected] github.com
github.com/ArcadeAI/arcade-mcp/commit/44660d18ceb220600401303df860a31ca7... [email protected] github.com
github.com/ArcadeAI/arcade-mcp/pull/691 [email protected] github.com
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