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Vulnerability · Published Sep 17, 2026 · Assigned by GitHub_M

CVE-2026-54504MCP Documentation Server: Web UI API binds to all interfaces without authentication by default

High 8.8

In plain English

A high-severity missing authentication in mcp-documentation-server from andrea9293. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 48% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.8High
Exploit odds (30 days)0.6%top 52.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
npm@andrea9293/mcp-documentation-server1.13.1GHSA-6f5r-5672-72j7

Affected products (as reported)

VendorProductVersions
andrea9293 mcp-documentation-server >= 1.13.0, < 1.13.1

Weakness: CWE-306, CWE-668 · Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References