CVE-2026-126393

EUVD-2026-125172
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.
SSRF
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
6.1 MEDIUM
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: 16.38%
Common Weakness Enumeration
References
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-6pg3-pqxw-jm82
https://www.vulncheck.com/advisories/siyuan-before-3.8.10-ssrf-via-skill-install-download-redirect-and-dns-rebinding