Auth bypass in Siyuan-Note Siyuan
CVE-2026-72800
SiYuan versions before v3.7.4 fail to apply publish-access filtering to the getAttributeViewKeysByID endpoint, allowing authenticated readers to retrieve complete database column schemas including descriptions, select vocabularies, and template expressions. Additionally, getBlockDefIDsByRefText and getBlockRelevantIDs endpoints enumerate workspace-wide block IDs without publish scoping, enabling attackers to discover valid block identifiers across publish boundaries and access content from hidden or password-protected documents.
Vulnerability class: Broken Access Control
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-5fhr-f75j-8wr9 (vendor-advisory)
- www.vulncheck.com/advisories/siyuan-before-information-disclosure-via-unfiltere… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-72800?
- CVE-2026-72800 is a medium-severity vulnerability in Siyuan-Note Siyuan, classified under Missing Authorization. CVSS score: 5.8/10. Published 2026-08-12.
- How severe is CVE-2026-72800?
- Medium severity. CVSS v3 base score is 5.8 out of 10.