What is CVE-2026-109309?

CVE-2026-109309 is a medium-severity vulnerability in Siyuan-Note Siyuan, classified under Path Traversal. CVSS score: 6.5/10. Published 2026-10-12.

How severe is CVE-2026-109309?

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

Path Traversal in Siyuan-Note Siyuan

CVE-2026-109309

SiYuan v3.7.0 before v3.8.6 contains an absolute path traversal vulnerability in the kernel's private plugin HTTP server, which passes a kernel plugin handler's ResponseFile.Path to gin's Context.File without validation. Attackers supplying a malicious kernel plugin can return an absolute path to read any file readable by the SiYuan process, including the API token and conf.json.

Vulnerability class: Path Traversal (Directory Traversal)

Published 2026-10-12 · last modified 2026-10-12.

CVSS v3 metric

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

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Siyuan-Note Siyuan

Weakness classification (CWE)

CWE-22 — Path Traversal

References

github.com/siyuan-note/siyuan/security/advisories/GHSA-phmw-4rgv-r4xv (vendor-advisory)
github.com/siyuan-note/siyuan/commit/c6494375ea40ee973f430f0e85d50f1862a30d81 (patch)
www.vulncheck.com/advisories/siyuan-3.7.0-before-3.8.6-arbitrary-file-read-via-… (third-party-advisory)

Frequently asked questions

What is CVE-2026-109309?: CVE-2026-109309 is a medium-severity vulnerability in Siyuan-Note Siyuan, classified under Path Traversal. CVSS score: 6.5/10. Published 2026-10-12.
How severe is CVE-2026-109309?: Medium severity. CVSS v3 base score is 6.5 out of 10.