Auth bypass in Siyuan-Note Siyuan
CVE-2026-93921
SiYuan versions through 3.8.4 fail to enforce publish access control in the getDynamicIcon endpoint, allowing read-only token holders to access document metadata. Attackers can call the endpoint with type=8 and crafted content to read block titles, names, aliases, and hierarchical paths of restricted documents via template injection.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.004 (31.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 31.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
Weakness classification (CWE)
References
- github.com/siyuan-note/siyuan/security/advisories/GHSA-whcx-xxqh-c838 (vendor-advisory)
- github.com/siyuan-note/siyuan (product)
- github.com/siyuan-note/siyuan/blob/v3.8.4/kernel/api/router.go (technical-description)
- github.com/siyuan-note/siyuan/blob/v3.8.4/kernel/model/template.go (technical-description)
- github.com/siyuan-note/siyuan/blob/v3.8.4/kernel/api/icon.go (technical-description)
- www.vulncheck.com/advisories/siyuan-through-3.8.4-access-control-bypass-via-dyn… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-93921?
- CVE-2026-93921 is a medium-severity vulnerability in Siyuan-Note Siyuan, classified under Missing Authorization. CVSS score: 4.3/10. Published 2026-09-19.
- How severe is CVE-2026-93921?
- Medium severity. CVSS v3 base score is 4.3 out of 10.