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.
Advisories

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Fixes

Solution

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Workaround

No workaround given by the vendor.

History

Fri, 04 Sep 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 04 Sep 2026 14:30:00 +0000

Type Values Removed Values Added
First Time appeared Siyuan
Siyuan siyuan
Vendors & Products Siyuan
Siyuan siyuan

Fri, 04 Sep 2026 11:45:00 +0000

Type Values Removed Values Added
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.
Title SiYuan before v3.8.2 Path Guard Bypass via Case Mismatch
First Time appeared B3log
B3log siyuan
Weaknesses CWE-22
CPEs cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*
Vendors & Products B3log
B3log siyuan
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N'}

cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-09-04T14:07:28.189Z

Reserved: 2026-09-04T10:56:22.464Z

Link: CVE-2026-85580

cve-icon Vulnrichment

Updated: 2026-09-04T14:06:29.168Z

cve-icon NVD

Status : Received

Published: 2026-09-04T12:17:19.917

Modified: 2026-09-04T15:17:39.600

Link: CVE-2026-85580

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-04T14:15:07Z

Weaknesses