{"cve":"CVE-2025-66454","nvd":{"published":"2025-12-02T19:15:52.683","modified":"2026-10-18T18:10:00.100","status":"Deferred","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","score":6.5},"cwes":["CWE-321","CWE-798"],"references":["https://github.com/ArcadeAI/arcade-mcp/commit/44660d18ceb220600401303df860a31ca766c817","https://github.com/ArcadeAI/arcade-mcp/pull/691","https://github.com/ArcadeAI/arcade-mcp/security/advisories/GHSA-g2jx-37x6-6438"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:16:02.354564667+00:00"},"epss":{"cve":"CVE-2025-66454","score":0.00313,"percentile":0.23999,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-g2jx-37x6-6438","url":"https://osv.dev/vulnerability/GHSA-g2jx-37x6-6438","summary":"arcade-mcp-server Has Default Hardcoded Worker Secret That Allows Full Unauthorized Access to All HTTP MCP Worker Endpoints","modified":"2026-07-07T17:57:36.743751455Z","packages":[{"ecosystem":"PyPI","name":"arcade-mcp-server","purl":"pkg:pypi/arcade-mcp-server","ranges":["<1.9.1"],"fixed":["1.9.1"]}]},{"id":"PYSEC-2026-1192","url":"https://osv.dev/vulnerability/PYSEC-2026-1192","summary":"arcade-mcp-server Has Default Hardcoded Worker Secret That Allows Full Unauthorized Access to All HTTP MCP Worker Endpoints","modified":"2026-07-07T17:47:11.010147192Z","packages":[{"ecosystem":"PyPI","name":"arcade-mcp-server","purl":"pkg:pypi/arcade-mcp-server","ranges":["<1.9.1"],"fixed":["1.9.1"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}