CVE-2026-85580

7.1 highEPSS 0.6%

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.

Severity

CVSS 4.0

7.1 high

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

CVSS 3.1

6.5 medium

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

EPSS: 0.6% chance of exploitation in the next 30 days; higher than 47% of CVEs (scores of 2026-10-31)
CWE: CWE-22
Published: 2026-09-04
Modified: 2026-09-08
Record from: the NVD, synced 2026-10-19

References

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

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