CVE-2026-85580

high

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.

References

https://www.vulncheck.com/advisories/siyuan-before-3.8.2-path-guard-bypass-via-case-mismatch

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

Details

Source: Mitre, NVD

Published: 2026-09-04

Updated: 2026-09-08

Risk Information

CVSS v2

Base Score: 6.8

Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:N/A:N

Severity: Medium

CVSS v3

Base Score: 6.5

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

Severity: Medium

CVSS v4

Base 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

Severity: High

EPSS

EPSS: 0.00526