{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-126776", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-11-11T18:27:27.098Z", "datePublished": "2026-11-11T18:41:08.401Z", "dateUpdated": "2026-11-11T18:41:08.401Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-11-11T18:41:08.401Z"}, "datePublic": "2026-11-01T07:30:20.000Z", "title": "SiYuan 3.7.0 before 3.8.10 Path Traversal File Write via MCP web_fetch", "descriptions": [{"lang": "en", "value": "SiYuan 3.7.0 before 3.8.10 on Windows contains a path traversal vulnerability in kernel/util/webfetch.go that allows attackers to write files outside the import directory via backslash-encoded filenames. Attackers controlling a URL fetched by the MCP web_fetch or http_request tools can use %5C-encoded ..\\ sequences to write chosen response bytes to directories above temp/import that are writable by the SiYuan user."}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')", "cweId": "CWE-22", "type": "CWE"}]}], "affected": [{"vendor": "siyuan-note", "product": "siyuan", "defaultStatus": "unaffected", "versions": [{"version": "3.7.0", "lessThan": "3.8.10", "status": "affected", "versionType": "semver"}, {"version": "3.8.10", "status": "unaffected", "versionType": "semver"}], "packageURL": "pkg:golang/github.com/siyuan-note/siyuan/kernel", "repo": "https://github.com/siyuan-note/siyuan"}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.7.0", "versionEndExcluding": "3.8.10"}]}]}], "metrics": [{"format": "CVSS", "cvssV4_0": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 6, "baseSeverity": "MEDIUM"}}, {"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "availabilityImpact": "NONE", "baseScore": 5.3, "baseSeverity": "MEDIUM"}}], "references": [{"url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-hq2c-hh95-vrr6", "tags": ["vendor-advisory"], "name": "GitHub Security Advisory (GHSA-hq2c-hh95-vrr6)"}, {"url": "https://github.com/siyuan-note/siyuan/commit/94d6a42a0362c0a6938a29ab84addb1fe0aca21c", "tags": ["patch"]}, {"url": "https://github.com/siyuan-note/siyuan/releases/tag/v3.8.10", "tags": ["release-notes"], "name": "siyuan v3.8.10 Release Notes"}, {"url": "https://github.com/siyuan-note/siyuan/blob/v3.7.0/kernel/util/webfetch.go#L155", "tags": ["technical-description"]}, {"name": "VulnCheck Advisory: SiYuan 3.7.0 before 3.8.10 Path Traversal File Write via MCP web_fetch", "tags": ["third-party-advisory"], "url": "https://www.vulncheck.com/advisories/siyuan-3.7.0-before-3.8.10-path-traversal-file-write-via-mcp-web-fetch"}], "credits": [{"lang": "en", "value": "Zachariah Mithani (AploSec)", "type": "finder"}], "x_generator": {"engine": "vulncheck-endgame"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "packageURL": "pkg:golang/github.com/siyuan-note/siyuan/kernel", "product": "siyuan", "repo": "https://github.com/siyuan-note/siyuan", "vendor": "siyuan-note", "versions": [{"lessThan": "3.8.10", "status": "affected", "version": "3.7.0", "versionType": "semver"}, {"status": "unaffected", "version": "3.8.10", "versionType": "semver"}]}], "source": "disclosure@vulncheck.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "SiYuan 3.7.0 before 3.8.10 on Windows contains a path traversal vulnerability in kernel/util/webfetch.go that allows attackers to write files outside the import directory via backslash-encoded filenames. Attackers controlling a URL fetched by the MCP web_fetch or http_request tools can use %5C-encoded ..\\ sequences to write chosen response bytes to directories above temp/import that are writable by the SiYuan user."}], "id": "CVE-2026-126776", "lastModified": "2026-11-11T19:17:38.443", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 1.6, "impactScore": 3.6, "source": "disclosure@vulncheck.com", "type": "Primary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 6.0, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "PASSIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/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", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "disclosure@vulncheck.com", "type": "Secondary"}]}, "published": "2026-11-11T19:17:38.287", "references": [{"source": "disclosure@vulncheck.com", "url": "https://github.com/siyuan-note/siyuan/blob/v3.7.0/kernel/util/webfetch.go#L155"}, {"source": "disclosure@vulncheck.com", "url": "https://github.com/siyuan-note/siyuan/commit/94d6a42a0362c0a6938a29ab84addb1fe0aca21c"}, {"source": "disclosure@vulncheck.com", "url": "https://github.com/siyuan-note/siyuan/releases/tag/v3.8.10"}, {"source": "disclosure@vulncheck.com", "url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-hq2c-hh95-vrr6"}, {"source": "disclosure@vulncheck.com", "url": "https://www.vulncheck.com/advisories/siyuan-3.7.0-before-3.8.10-path-traversal-file-write-via-mcp-web-fetch"}], "sourceIdentifier": "disclosure@vulncheck.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-22"}], "source": "disclosure@vulncheck.com", "type": "Primary"}]}

{}

{}