CVE-2026-66012

{
  "id": "CVE-2026-66012",
  "sourceIdentifier": "[email protected]",
  "published": "2026-07-25T11:17:19.053",
  "lastModified": "2026-10-24T13:10:00.147",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "SiYuan before v3.7.2 contains a missing authorization vulnerability in the POST /mcp kernel endpoint, which is gated only by a general auth check (model.CheckAuth) with no admin-role or read-only enforcement. This exposes 31 MCP tools, including a file tool with list/read/write/delete/rename/copy actions across the entire workspace. When the Publish server is enabled in anonymous mode (Conf.Publish.Enable=true and Conf.Publish.Auth.Enable=false), the Publish reverse proxy attaches an anonymous RoleReader JWT to proxied requests, allowing a remote unauthenticated attacker to reach /mcp. The attacker can read conf/conf.json to extract accessAuthCode, api.token, and cookieKey in plaintext, write arbitrary files in the workspace, and plant a plugin into data/plugins/ that executes with nodeIntegration:true and no contextIsolation on the next desktop launch, leading to administrator takeover."
    },
    {
      "lang": "es",
      "value": "SiYuan antes de v3.7.2 contiene una vulnerabilidad de autorización faltante en el endpoint del kernel POST /mcp, que está protegido solo por una verificación de autenticación general (model.CheckAuth) sin aplicación de rol de administrador o de solo lectura. Esto expone 31 herramientas MCP, incluyendo una herramienta de archivos con acciones de listar/leer/escribir/eliminar/renombrar/copiar en todo el espacio de trabajo. Cuando el servidor de publicación está habilitado en modo anónimo (Conf.Publish.Enable=true y Conf.Publish.Auth.Enable=false), el proxy inverso de publicación adjunta un JWT RoleReader anónimo a las solicitudes proxy, permitiendo a un atacante remoto no autenticado alcanzar /mcp. El atacante puede leer conf/conf.json para extraer accessAuthCode, API.token y cookieKey en texto plano, escribir archivos arbitrarios en el espacio de trabajo y plantar un plugin en data/plugins/ que se ejecuta con nodeIntegration:true y sin contextIsolation en el próximo inicio de escritorio, lo que lleva a la toma de control del administrador."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "siyuan-note",
          "product": "siyuan",
          "defaultStatus": "unaffected",
          "packageURL": "pkg:golang/github.com/siyuan-note/siyuan",
          "versions": [
            {
              "version": "0",
              "lessThan": "3.7.2",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "3.7.2",
              "versionType": "semver",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "baseScore": 10.0,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnAvailabilityImpact": "HIGH",
          "subConfidentialityImpact": "HIGH",
          "subIntegrityImpact": "HIGH",
          "subAvailabilityImpact": "HIGH",
          "exploitMaturity": "NOT_DEFINED",
          "confidentialityRequirement": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "valueDensity": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
          "baseScore": 10.0,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "CHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 6.0
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-07-27T14:06:39.063655Z",
          "id": "CVE-2026-66012",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-862"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/siyuan-note/siyuan/commit/c72ca4cd09019e5f64afdee8f8c6ec5ef34858db",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-cvhv-7xhj-xjp8",
      "source": "[email protected]"
    },
    {
      "url": "https://www.vulncheck.com/advisories/siyuan-before-unauthenticated-administrator-takeover-via-mcp",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-cvhv-7xhj-xjp8",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ]
}