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CVE-2020-26286

Status: ModifiedHigh (7.5)—

HedgeDoc is a collaborative platform for writing and sharing markdown. In HedgeDoc before version 1.7.1 an unauthenticated attacker can upload arbitrary files to the upload storage backend including HTML, JS and PHP files. The problem is patched in HedgeDoc 1.7.1. You should however verify that your uploaded file storage only contains files that are allowed, as uploaded files might still be served. As workaround it's possible to block the `/uploadimage` endpoint on your instance using your reverse proxy. And/or restrict MIME-types and file names served from your upload file storage.

CVSS

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (1)

Hedgedoc — Hedgedoc

CWEs

References

Raw JSON (NVD)

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{
  "id": "CVE-2020-26286",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 5,
          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:L/Au:N/C:N/I:P/A:N",
          "authentication": "NONE",
          "integrityImpact": "PARTIAL",
          "accessComplexity": "LOW",
          "availabilityImpact": "NONE",
          "confidentialityImpact": "NONE"
        },
        "acInsufInfo": false,
        "impactScore": 2.9,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 10,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "security-advisories@github.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.5,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 3.9
      },
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.5,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "security-advisories@github.com",
      "affectedData": [
        {
          "vendor": "hedgedoc",
          "product": "hedgedoc",
          "versions": [
            {
              "status": "affected",
              "version": "< 1.7.1"
            }
          ]
        }
      ]
    }
  ],
  "published": "2020-12-29T00:15:12.593",
  "references": [
    {
      "url": "https://github.com/hedgedoc/hedgedoc/commit/e9306991cdb5ff2752c1eeba3fedba42aec3c2d8",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/hedgedoc/hedgedoc/releases/tag/1.7.1",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-wcr3-xhv7-8gxc",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/hedgedoc/hedgedoc/commit/e9306991cdb5ff2752c1eeba3fedba42aec3c2d8",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://github.com/hedgedoc/hedgedoc/releases/tag/1.7.1",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-wcr3-xhv7-8gxc",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "security-advisories@github.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-434"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "HedgeDoc is a collaborative platform for writing and sharing markdown. In HedgeDoc before version 1.7.1 an unauthenticated attacker can upload arbitrary files to the upload storage backend including HTML, JS and PHP files. The problem is patched in HedgeDoc 1.7.1. You should however verify that your uploaded file storage only contains files that are allowed, as uploaded files might still be served. As workaround it's possible to block the `/uploadimage` endpoint on your instance using your reverse proxy. And/or restrict MIME-types and file names served from your upload file storage."
    },
    {
      "lang": "es",
      "value": "HedgeDoc es una plataforma colaborativa para escribir y compartir rebajas.&#xa0;En HedgeDoc versiones anteriores a 1.7.1, un atacante no autenticado puede cargar archivos arbitrarios al backend de almacenamiento de carga, incluyendo archivos HTML, JS y PHP.&#xa0;El problema está parcheado en HedgeDoc versión 1.7.1.&#xa0;Sin embargo, debe verificar que el almacenamiento de archivos cargados solo contenga archivos permitidos, ya que es posible que los archivos cargados aún puedan ser servidos.&#xa0;Como solución alternativa, es posible bloquear el endpoint \"/uploadimage\" en su instancia usando su proxy inverso.&#xa0;Y/o restringir los tipos MIME y los nombres de archivo que se proporcionan desde el almacenamiento de archivos de carga"
    }
  ],
  "lastModified": "2026-06-17T03:08:00.100",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:hedgedoc:hedgedoc:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "DB55BE58-3D3F-40C5-89FE-2AACEA56F4E0",
              "versionEndExcluding": "1.7.1"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "security-advisories@github.com"
}