cvedb.io
CVE-2026-55605
MEDIUM · CVSS 5.3
EPSS exploitation probability: 0%
Published 2026-07-09T22:17:06.400 · Last modified 2026-07-09T22:17:06.400

Summary

DeepSeek MCP Server is an MCP server for DeepSeek V4. Starting in version 1.4.2 and prior to version 1.8.0, the self-hosted HTTP transport of `@arikusi/deepseek-mcp-server` exposes `POST /mcp` without any authentication: `createMcpExpressApp` is called without an `authProvider` and no middleware guards the route, so any network-reachable client can issue an unauthenticated `initialize` request and obtain a valid MCP session identifier. In reproduced testing against commit `5e1302171e99`, an unauthenticated client was able to initialize a session, enumerate tools, and invoke the local `deepseek_sessions` tool with no credentials. The same unauthenticated session also exposes `deepseek_chat`, whose handler uses the server-side `DEEPSEEK_API_KEY` when self-hosted deployments configure one. Th

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.