CVE-2026-33976

{
  "id": "CVE-2026-33976",
  "sourceIdentifier": "[email protected]",
  "published": "2026-03-27T22:16:22.250",
  "lastModified": "2026-10-26T21:10:00.170",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Notesnook is a note-taking app. Prior to version 3.3.11 on Web/Desktop and 3.3.17 on Android/iOS, a stored XSS in the Web Clipper rendering flow can be escalated to remote code execution in the desktop app. The root cause is that the clipper preserves attacker-controlled attributes from the source page’s root element and stores them inside web-clip HTML. When the clip is later opened, Notesnook renders that HTML into a same-origin, unsandboxed iframe using `contentDocument.write(...)`. Event-handler attributes such as `onload`, `onclick`, or `onmouseover` execute in the Notesnook origin. In the desktop app, this becomes RCE because Electron is configured with `nodeIntegration: true` and `contextIsolation: false`. Version 3.3.11 Web/Desktop and 3.3.17 on Android/iOS patch the issue."
    },
    {
      "lang": "es",
      "value": "Notesnook es una aplicación para tomar notas. Antes de la versión 3.3.11 en Web/Escritorio y 3.3.17 en Android/iOS, un XSS almacenado en el flujo de renderizado de Web Clipper puede escalarse a ejecución remota de código en la aplicación de escritorio. La causa raíz es que el clipper preserva atributos controlados por el atacante del elemento raíz de la página de origen y los almacena dentro del HTML del web-clip. Cuando el clip se abre posteriormente, Notesnook renderiza ese HTML en un iframe de mismo origen y sin sandbox usando ’contentDocument.write(...)’. Atributos de gestor de eventos como ’onload’, ’onclick’ o ’onmouseover’ se ejecutan en el origen de Notesnook. En la aplicación de escritorio, esto se convierte en RCE porque Electron está configurado con ’nodeIntegration: true’ y ’contextIsolation: false’. La versión 3.3.11 Web/Escritorio y 3.3.17 en Android/iOS parchean el problema."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "streetwriters",
          "product": "Notesnook Web/Desktop",
          "versions": [
            {
              "version": "< 3.3.11",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "streetwriters",
          "product": "Notesnook iOS/Android",
          "versions": [
            {
              "version": "< 3.3.17",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H",
          "baseScore": 9.6,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "REQUIRED",
          "scope": "CHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 6.0
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-03-31T00:00:00+00:00",
          "id": "CVE-2026-33976",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-79"
        },
        {
          "lang": "en",
          "value": "CWE-94"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:streetwriters:notesnook_desktop:*:*:*:*:*:*:*:*",
              "versionEndExcluding": "3.3.11",
              "matchCriteriaId": "08C11EDB-67C1-4E85-A07D-0164CB036757"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:streetwriters:notesnook_mobile:*:*:*:*:*:android:*:*",
              "versionEndExcluding": "3.3.17",
              "matchCriteriaId": "105C802D-D317-4B9A-B883-D07A1E0840E6"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:streetwriters:notesnook_mobile:*:*:*:*:*:iphone_os:*:*",
              "versionEndExcluding": "3.3.17",
              "matchCriteriaId": "858B01C2-38C3-4093-A638-E380119ABDF5"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/streetwriters/notesnook/security/advisories/GHSA-f42f-phvp-43x5",
      "source": "[email protected]",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ]
    }
  ]
}