CVE-2026-34600

{
  "id": "CVE-2026-34600",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-34600",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-05-20T14:10:05.523690Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "security-advisories@github.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 5.7,
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N",
          "integrityImpact": "NONE",
          "userInteraction": "REQUIRED",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 2.1
      }
    ]
  },
  "affected": [
    {
      "source": "security-advisories@github.com",
      "affectedData": [
        {
          "vendor": "laurent22",
          "product": "joplin",
          "versions": [
            {
              "status": "affected",
              "version": "< 3.5.3"
            }
          ]
        }
      ]
    }
  ],
  "published": "2026-05-19T23:16:57.290",
  "references": [
    {
      "url": "https://github.com/laurent22/joplin/issues/14110",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/laurent22/joplin/pull/14289",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/laurent22/joplin/security/advisories/GHSA-88x4-77rc-jw94",
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/laurent22/joplin/security/advisories/GHSA-88x4-77rc-jw94",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ],
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "security-advisories@github.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-200"
        },
        {
          "lang": "en",
          "value": "CWE-281"
        },
        {
          "lang": "en",
          "value": "CWE-863"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Versions 3.5.2 and prior contain a logic error in the delta API that allows share recipients to download notes that are no longer shared with them, related to but not fully fixed by the prior patch in #14289. In ChangeModel.delta, when DELTA_INCLUDES_ITEMS is enabled (the default), the latest state of items is attached to delta output without verifying that those items are still shared with the requesting user, and the existing removal logic only filters items deleted for all users. Additionally, the change compression logic incorrectly reduces create - delete to NOOP, which is unsafe because compression is applied per page and an item can have multiple create events; if an earlier create falls on a separate page from a later create -> delete pair, the deletion is dropped and the sequence collapses to a create. As a result, the delta API returns a create event for a deleted item with the full latest content attached, exposing notes the user no longer has access to. This issue has been fixed in version 3.5.3."
    },
    {
      "lang": "es",
      "value": "Joplin es una aplicación de toma de notas y de tareas pendientes de código abierto que organiza notas y listas en cuadernos. Las versiones 3.5.2 y anteriores contienen un error de lógica en la API delta que permite a los destinatarios de la compartición descargar notas que ya no están compartidas con ellos, relacionado con, pero no completamente solucionado por el parche anterior en el #14289. En ChangeModel.delta, cuando DELTA_INCLUDES_ITEMS está habilitado (el valor predeterminado), el estado más reciente de los elementos se adjunta a la salida delta sin verificar que esos elementos sigan compartidos con el usuario solicitante, y la lógica de eliminación existente solo filtra los elementos eliminados para todos los usuarios. Además, la lógica de compresión de cambios reduce incorrectamente create - delete a NOOP, lo cual es inseguro porque la compresión se aplica por página y un elemento puede tener múltiples eventos de creación; si una creación anterior cae en una página separada de un par posterior create -> delete, la eliminación se descarta y la secuencia se colapsa a una creación. Como resultado, la API delta devuelve un evento de creación para un elemento eliminado con el contenido completo más reciente adjunto, exponiendo notas a las que el usuario ya no tiene acceso. Este problema ha sido solucionado en la versión 3.5.3."
    }
  ],
  "lastModified": "2026-07-24T09:10:00.153",
  "sourceIdentifier": "security-advisories@github.com"
}