CVE-2026-54504

MCP Documentation Server: Web UI API binds to all interfaces without authentication by default

State
Published
Severity
8.8 High
Published
Sep 17, 2026
Updated
Sep 17, 2026
Reserved
Jun 15, 2026

Read the record on cve.org

Description

MCP Documentation Server is a local-first document management and semantic search server for AI coding agents. From 1.13.0 until 1.13.1, the automatically started Web UI in src/server.ts calls startWebServer in src/web-server.ts with START_WEB_UI enabled by default and WEB_PORT set to 3080. startWebServer uses app.listen(PORT) without a host, which binds the unauthenticated document-management API to all interfaces rather than localhost. A network-reachable client can invoke GET /api/documents, GET /api/documents/:id, POST /api/documents, POST /api/search-all, DELETE /api/documents/:id, and GET /api/config without credentials to enumerate and read documents, search the corpus, insert or delete documents, and tamper with the MCP assistant's knowledge base. The service must be reachable from the attacker's LAN, VM network, container bridge, VPN, or another routed network, and the issue does not provide remote code execution. This issue is fixed in 1.13.1.

Scores

CVSSScoreVectorSource
3.18.8 HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HGitHub_M

Weaknesses

  • CWE-306 Missing Authentication for Critical Function
  • CWE-668 Exposure of Resource to Wrong Sphere

Affected Products

ProductVersions
mcp-documentation-serverandrea9293
  • >= 1.13.0, < 1.13.1Affected

References

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