CVE-2026-85580

Medium

Description

SiYuan versions before v3.8.2 contain a path guard bypass vulnerability in the MCP file-access handler that uses case-sensitive matching on Linux filesystems. Attackers can read the protected publishAccess.json file by requesting case-variant paths like PublishAccess.json to disclose sensitive publish-access configuration and metadata.

SeverityMedium

CVSS6.5

Exploit probability—

ProductSiyuan

PublishedSep 4, 2026

First seenSep 4, 2026

Weakness typeCWE-22Path traversal

How to fix

Update

siyuan-note siyuan3.8.2 or later

Vendor advisories

github.com/siyuan-note/siyuan/security/advisories/GHSA-mmgw-3mx9-cfwp

Affected products

Product	Affected versions	Fixed in
siyuan-note siyuan	v < 3.8.2	3.8.2

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