{"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"}}}}