What is CVE-2026-85580?

CVE-2026-85580 is a medium-severity vulnerability, classified under Path Traversal. CVSS score: 6.5/10. Published 2026-09-04.

How severe is CVE-2026-85580?

Medium severity. CVSS v3 base score is 6.5 out of 10.

CVE-2026-85580

CVE-2026-85580

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.

Vulnerability class: Path Traversal (Directory Traversal)

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

Weakness classification (CWE)

CWE-22 — Path Traversal

References

disclosure@vulncheck.com
disclosure@vulncheck.com

Frequently asked questions

What is CVE-2026-85580?: CVE-2026-85580 is a medium-severity vulnerability, classified under Path Traversal. CVSS score: 6.5/10. Published 2026-09-04.
How severe is CVE-2026-85580?: Medium severity. CVSS v3 base score is 6.5 out of 10.