CVE-2026-85580

MEDIUM 6.5

SiYuan before v3.8.2 Path Guard Bypass via Case Mismatch

CVSS Score

6.5

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-22
Vendor	siyuan-note
Product	siyuan
Published	Sep 4, 2026
Last Updated	Sep 4, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Affected Versions

siyuan-note / siyuan

0 < 3.8.2

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/siyuan-note/siyuan/security/advisories/GHSA-mmgw-3mx9-cfwp vulncheck.com: https://www.vulncheck.com/advisories/siyuan-before-3.8.2-path-guard-bypass-via-case-mismatch