Auth bypass in Siyuan-Note Siyuan
CVE-2026-73606
SiYuan versions before v3.7.4 contain an information disclosure vulnerability in the /api/block/getRefIDs endpoint that fails to check password-protected document tiers. Unauthenticated readers can discover that password-protected documents reference specific blocks and obtain block identifiers without entering the document password.
Vulnerability class: IDOR (Insecure Direct Object Reference)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.003 (23.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 23.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
- Siyuan-Note Siyuan — versions 0, 3.7.4
Weakness classification (CWE)
References
- github.com/siyuan-note/siyuan/security/advisories/GHSA-vg99-7gj7-2fr5 (vendor-advisory)
- www.vulncheck.com/advisories/siyuan-before-information-disclosure-via-getrefids (third-party-advisory)
Frequently asked questions
- What is CVE-2026-73606?
- CVE-2026-73606 is a medium-severity vulnerability in Siyuan-Note Siyuan, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 5.8/10. Published 2026-08-13.
- How severe is CVE-2026-73606?
- Medium severity. CVSS v3 base score is 5.8 out of 10.