CVE-2026-66012

{"id": "CVE-2026-66012", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-66012", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "yes"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-07-27T14:06:39.063655Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "disclosure@vulncheck.com", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 10.0, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 6.0, "exploitabilityScore": 3.9}], "cvssMetricV40": [{"type": "Secondary", "source": "disclosure@vulncheck.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 10.0, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "valueDensity": "NOT_DEFINED", "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", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "HIGH", "vulnConfidentialityImpact": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "disclosure@vulncheck.com", "affectedData": [{"vendor": "siyuan-note", "product": "siyuan", "versions": [{"status": "affected", "version": "0", "lessThan": "3.7.2", "versionType": "semver"}, {"status": "unaffected", "version": "3.7.2", "versionType": "semver"}], "packageURL": "pkg:golang/github.com/siyuan-note/siyuan", "defaultStatus": "unaffected"}]}], "published": "2026-07-25T11:17:19.053", "references": [{"url": "https://github.com/siyuan-note/siyuan/commit/c72ca4cd09019e5f64afdee8f8c6ec5ef34858db", "source": "disclosure@vulncheck.com"}, {"url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-cvhv-7xhj-xjp8", "source": "disclosure@vulncheck.com"}, {"url": "https://www.vulncheck.com/advisories/siyuan-before-unauthenticated-administrator-takeover-via-mcp", "source": "disclosure@vulncheck.com"}, {"url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-cvhv-7xhj-xjp8", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Deferred", "weaknesses": [{"type": "Secondary", "source": "disclosure@vulncheck.com", "description": [{"lang": "en", "value": "CWE-862"}]}], "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 autorizaci\u00f3n faltante en el endpoint del kernel POST /mcp, que est\u00e1 protegido solo por una verificaci\u00f3n de autenticaci\u00f3n general (model.CheckAuth) sin aplicaci\u00f3n 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 publicaci\u00f3n est\u00e1 habilitado en modo an\u00f3nimo (Conf.Publish.Enable=true y Conf.Publish.Auth.Enable=false), el proxy inverso de publicaci\u00f3n adjunta un JWT RoleReader an\u00f3nimo 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 pr\u00f3ximo inicio de escritorio, lo que lleva a la toma de control del administrador."}], "lastModified": "2026-10-24T13:10:00.147", "sourceIdentifier": "disclosure@vulncheck.com"}