{
  "document": {
    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
    "distribution": {
      "tlp": {
        "label": "WHITE"
      }
    },
    "lang": "nl",
    "notes": [
      {
        "category": "legal_disclaimer",
        "text": "The Netherlands Cyber Security Center (henceforth: NCSC-NL) maintains this page to enhance access to its information and security advisories. The use of this security advisory is subject to the following terms and conditions:\n\n    NCSC-NL makes every reasonable effort to ensure that the content of this page is kept up to date, and that it is accurate and complete. Nevertheless, NCSC-NL cannot entirely rule out the possibility of errors, and therefore cannot give any warranty in respect of its completeness, accuracy or continuous keeping up-to-date. The information contained in this security advisory is intended solely for the purpose of providing general information to professional users. No rights can be derived from the information provided therein.\n\n    NCSC-NL and the Kingdom of the Netherlands assume no legal liability or responsibility for any damage resulting from either the use or inability of use of this security advisory. This includes damage resulting from the inaccuracy of incompleteness of the information contained in the advisory.\n    This security advisory is subject to Dutch law. All disputes related to or arising from the use of this advisory will be submitted to the competent court in The Hague. This choice of means also applies to the court in summary proceedings."
      },
      {
        "category": "description",
        "text": "N8n heeft een kwetsbaarheid verholpen in versies onder 1.121.0.",
        "title": "Feiten"
      },
      {
        "category": "description",
        "text": "De kwetsbaarheid in stelt ongeautoriseerde externe kwaadwillenden in staat om via specifieke, formuliergebaseerde workflows toegang te krijgen tot bestanden op de onderliggende server. Hierdoor kan gevoelige informatie die op het systeem is opgeslagen worden blootgesteld en kan, afhankelijk van de configuratie van de omgeving en het gebruik van workflows, verdere compromittering plaatsvinden. Deze beveiligingsfout is verholpen in versie 1.121.0.\n\nOnderzoekers hebben een proof-of-concept (PoC) gepubliceerd en gezien het wijdverbreide gebruik van n8n acht het NCSC het waarschijnlijk dat pogingen tot misbruik zullen toenemen. \n\nHet NCSC adviseert om:\n\n- N8n naar versie 1.121.0 of hoger bij te werken.\n- Maak n8n alleen via het internet bereikbaar als dit strikt noodzakelijk is.\n- Vereis authenticatie voor alle aangemaakte formulieren.\n",
        "title": "Interpretaties"
      },
      {
        "category": "description",
        "text": "N8n heeft deze kwetsbaarheid in de versie 1.121.0 verholpen.  Zie bijgevoegde referenties voor meer informatie.",
        "title": "Oplossingen"
      },
      {
        "category": "general",
        "text": "medium",
        "title": "Kans"
      },
      {
        "category": "general",
        "text": "high",
        "title": "Schade"
      },
      {
        "category": "general",
        "text": "Improper Input Validation",
        "title": "CWE-20"
      },
      {
        "category": "general",
        "text": "Improper Authentication",
        "title": "CWE-287"
      }
    ],
    "publisher": {
      "category": "coordinator",
      "contact_details": "cert@ncsc.nl",
      "name": "Nationaal Cyber Security Centrum",
      "namespace": "https://www.ncsc.nl/"
    },
    "references": [
      {
        "category": "external",
        "summary": "Reference",
        "url": "https://docs.n8n.io/"
      },
      {
        "category": "external",
        "summary": "Reference",
        "url": "https://www.cyera.com/research-labs/ni8mare-unauthenticated-remote-code-execution-in-n8n-cve-2026-21858"
      }
    ],
    "title": "Kwetsbaarheid verholpen in n8n",
    "tracking": {
      "current_release_date": "2026-01-08T12:34:29.315681Z",
      "generator": {
        "date": "2025-08-04T16:30:00Z",
        "engine": {
          "name": "V.A.",
          "version": "1.3"
        }
      },
      "id": "NCSC-2026-0002",
      "initial_release_date": "2026-01-08T12:34:29.315681Z",
      "revision_history": [
        {
          "date": "2026-01-08T12:34:29.315681Z",
          "number": "1.0.0",
          "summary": "Initiele versie"
        }
      ],
      "status": "final",
      "version": "1.0.0"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "vers:unknown/*",
                "product": {
                  "name": "vers:unknown/*",
                  "product_id": "CSAFPID-1"
                }
              }
            ],
            "category": "product_name",
            "name": "n8n"
          }
        ],
        "category": "vendor",
        "name": "n8n"
      },
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "vers:unknown/*",
                "product": {
                  "name": "vers:unknown/*",
                  "product_id": "CSAFPID-2"
                }
              }
            ],
            "category": "product_name",
            "name": "n8n"
          }
        ],
        "category": "vendor",
        "name": "n8n-io"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-21858",
      "cwe": {
        "id": "CWE-20",
        "name": "Improper Input Validation"
      },
      "notes": [
        {
          "category": "other",
          "text": "Improper Input Validation",
          "title": "CWE-20"
        },
        {
          "category": "description",
          "text": "A vulnerability in n8n versions below 1.121.0 allows unauthorized remote access to sensitive files, which has been addressed in version 1.121.0.",
          "title": "Summary"
        },
        {
          "category": "general",
          "text": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N",
          "title": "CVSSV4"
        }
      ],
      "product_status": {
        "known_affected": [
          "CSAFPID-1",
          "CSAFPID-2"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-21858 | NCSC-NL Website",
          "url": "https://vulnerabilities.ncsc.nl/csaf/v2/2026/cve-2026-21858.json"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "baseScore": 10.0,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N",
            "version": "3.1"
          },
          "products": [
            "CSAFPID-1",
            "CSAFPID-2"
          ]
        }
      ],
      "title": "CVE-2026-21858"
    }
  ]
}