CVE-2025-66454
Published: 02 December 2025
Summary
CVE-2025-66454 is a medium-severity Use of Hard-coded Cryptographic Key (CWE-321) vulnerability. Its CVSS base score is 6.5 (Medium).
Operationally, ranked in the top 44.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
This vulnerability is AI-related — categorised as AI Agent Protocols and Integrations; in the Protocol-Specific Risks risk domain.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-200280
Vulnerability details
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…
more
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.
- CWE(s)
AI Security AnalysisAI
- AI Category
- AI Agent Protocols and Integrations
- Risk Domain
- Protocol-Specific Risks
- OWASP Top 10 for LLMs 2025
- None mapped
- Classification Reason
- Matched keywords: mcp
Related Threats
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Supplier evaluation and secure acquisition practices make it harder for hard-coded credentials to be introduced via procured products.
Requiring security functional requirements and acceptance criteria allows contracts to prohibit hard-coded credentials in delivered systems or components.
Supplier risk reviews identify and discourage hard-coded credentials in delivered products or services.
Enables users to notice when hard-coded credentials have been exploited for unauthorized access.
Security training explicitly warns against hard-coded credentials, lowering their use in systems.
Policy and procedures prohibit hard-coded credentials in favor of managed authentication.
External identity providers eliminate the need for hard-coded credentials in applications.
Changing default authenticators prior to first use and protecting content prevents use of hard-coded credentials.