Vulnerability in Siyuan-Note Siyuan
CVE-2026-100638
SiYuan versions before v3.8.4 contain a path traversal vulnerability in the setNotebookIcon endpoint that allows authenticated administrators to create arbitrary directory trees and write files outside the workspace boundary. Attackers can supply directory traversal sequences in the notebook parameter to escape the workspace data directory and write conf.json files to arbitrary locations accessible by the kernel process.
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-6h8x-6mph-7438 (vendor-advisory)
- www.vulncheck.com/advisories/siyuan-before-3.8.4-path-traversal-via-setnotebook… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-100638?
- CVE-2026-100638 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-2026-100638?
- High severity. CVSS v3 base score is 7.6 out of 10.