Vulnerability in Siyuan-Note Siyuan
CVE-2026-100637
SiYuan versions before v3.8.4 contain a path traversal vulnerability in the checkoutRepo endpoint that allows authenticated administrators to write JSON files outside the workspace. Attackers can supply a sessionID parameter containing directory traversal sequences to overwrite arbitrary JSON files in pre-existing kernel-writable directories outside workspace boundaries.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:L.
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
Weakness classification (CWE)
References
- github.com/siyuan-note/siyuan/security/advisories/GHSA-jhmh-hr4g-c5g2 (vendor-advisory)
- www.vulncheck.com/advisories/siyuan-before-3.8.4-path-traversal-via-checkoutrep… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-100637?
- CVE-2026-100637 is a high-severity vulnerability in Siyuan-Note Siyuan, classified under External Control of File Name or Path. CVSS score: 7.6/10. Published 2026-09-26.
- How severe is CVE-2026-100637?
- High severity. CVSS v3 base score is 7.6 out of 10.