{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-66012", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-07-23T19:22:30.643Z", "datePublished": "2026-07-25T10:45:56.085Z", "dateUpdated": "2026-07-28T01:06:21.864Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-07-28T01:06:21.864Z" }, "datePublic": "2026-07-13T00:00:00.000Z", "title": "SiYuan before v3.7.2 Unauthenticated Administrator Takeover via MCP", "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." } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "description": "Missing Authorization", "cweId": "CWE-862", "type": "CWE" } ] } ], "affected": [ { "vendor": "siyuan-note", "product": "siyuan", "defaultStatus": "unaffected", "packageURL": "pkg:npm/github.com/siyuan-note/siyuan", "versions": [ { "version": "0", "status": "affected", "versionType": "semver", "lessThan": "3.7.2" }, { "version": "3.7.2", "status": "unaffected", "versionType": "semver" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*", "versionEndExcluding": "3.7.2" } ] } ] } ], "metrics": [ { "format": "CVSS", "cvssV4_0": { "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", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "HIGH", "subIntegrityImpact": "HIGH", "subAvailabilityImpact": "HIGH", "baseScore": 10, "baseSeverity": "CRITICAL" } }, { "format": "CVSS", "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH", "baseScore": 10, "baseSeverity": "CRITICAL" } } ], "references": [ { "url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-cvhv-7xhj-xjp8", "name": "GitHub Security Advisory (GHSA-cvhv-7xhj-xjp8)", "tags": [ "vendor-advisory" ] }, { "url": "https://github.com/siyuan-note/siyuan/commit/c72ca4cd09019e5f64afdee8f8c6ec5ef34858db", "name": "https://github.com/siyuan-note/siyuan/commit/c72ca4cd09019e5f64afdee8f8c6ec5ef34858db", "tags": [ "patch" ] }, { "name": "VulnCheck Advisory: SiYuan before v3.7.2 Unauthenticated Administrator Takeover via MCP", "tags": [ "third-party-advisory" ], "url": "https://www.vulncheck.com/advisories/siyuan-before-unauthenticated-administrator-takeover-via-mcp" } ], "credits": [ { "lang": "en", "value": "hypnguyen1209", "type": "reporter" } ], "x_generator": { "engine": "vulncheck-endgame" } }, "adp": [ { "references": [ { "url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-cvhv-7xhj-xjp8", "tags": [ "exploit" ] } ], "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2026-07-27T14:06:39.063655Z", "id": "CVE-2026-66012", "options": [ { "Exploitation": "poc" }, { "Automatable": "yes" }, { "Technical Impact": "total" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-07-27T14:06:51.119Z" } } ] } }