{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-126393","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","state":"PUBLISHED","assignerShortName":"VulnCheck","dateReserved":"2026-11-10T21:30:16.910Z","datePublished":"2026-11-13T09:35:52.971Z","dateUpdated":"2026-11-13T09:35:52.971Z"},"containers":{"cna":{"providerMetadata":{"orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck","dateUpdated":"2026-11-13T09:35:52.971Z"},"datePublic":"2026-10-29T00:00:00.000Z","title":"SiYuan before 3.8.10 SSRF via Skill-Install Download Redirect and DNS Rebinding","descriptions":[{"lang":"en","value":"SiYuan before 3.8.10 contains a server-side request forgery vulnerability in the skill-install download path because fetchBytes performs only a parse-time hostname check instead of using ssrfSafeClient. Attackers can supply a skill URL via the MCP skill install action that redirects or DNS-rebinds to loopback addresses, reaching internal services and metadata endpoints."}],"problemTypes":[{"descriptions":[{"lang":"en","description":"Server-Side Request Forgery (SSRF)","cweId":"CWE-918","type":"CWE"}]}],"affected":[{"vendor":"siyuan-note","product":"siyuan","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","versionType":"semver","lessThan":"3.8.10"},{"version":"3.8.10","status":"unaffected","versionType":"semver"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*","versionEndExcluding":"3.8.10"}]}]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"LOW","subAvailabilityImpact":"NONE","baseScore":5.3,"baseSeverity":"MEDIUM"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"CHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"NONE","baseScore":6.1,"baseSeverity":"MEDIUM"}}],"references":[{"url":"https://github.com/siyuan-note/siyuan/security/advisories/GHSA-6pg3-pqxw-jm82","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-6pg3-pqxw-jm82)"},{"name":"VulnCheck Advisory: SiYuan before 3.8.10 SSRF via Skill-Install Download Redirect and DNS Rebinding","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/siyuan-before-3.8.10-ssrf-via-skill-install-download-redirect-and-dns-rebinding"}],"credits":[{"lang":"en","value":"Figo5","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}}}}