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.

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History

Fri, 13 Nov 2026 09:45:00 +0000

Type Values Removed Values Added
Description 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.
Title SiYuan before 3.8.10 SSRF via Skill-Install Download Redirect and DNS Rebinding
First Time appeared B3log
B3log siyuan
Weaknesses CWE-918
CPEs cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*
Vendors & Products B3log
B3log siyuan
References
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}

cvssV4_0

{'score': 5.3, 'vector': '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'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-11-13T09:35:52.971Z

Reserved: 2026-11-10T21:30:16.910Z

Link: CVE-2026-126393

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2026-11-13T10:17:43.207

Modified: 2026-11-13T10:17:43.333

Link: CVE-2026-126393

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses