Auth bypass in B3log Siyuan
CVE-2026-34453
SiYuan is a personal knowledge management system. Prior to version 3.6.2, the publish service exposes bookmarked blocks from password-protected documents to unauthenticated visitors. In publish/read-only mode, /api/bookmark/getBookmark filters bookmark results by calling FilterBlocksByPublishAccess(nil, ...). Because the filter treats a nil context as authorized, it skips the publish password check and returns bookmarked blocks from documents configured as Protected. As a result, anyone who can access the publish service can retrieve content from protected documents without providing the required password, as long as at least one block in the document is bookmarked. This issue has been patched in version 3.6.2.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.015 (72.3th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 72nd percentile — 72.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.012 · newest: 0.015 · change: +0.002
Affected products
- B3log Siyuan
- Siyuan-Note Siyuan — versions < 3.6.2
Weakness classification (CWE)
References
- github.com/siyuan-note/siyuan/security/advisories/GHSA-c77m-r996-jr3q (Exploit, Vendor Advisory)
- github.com/siyuan-note/siyuan/issues/17246 (Issue Tracking)
- github.com/siyuan-note/siyuan/releases/tag/v3.6.2 (Release Notes)
Frequently asked questions
- What is CVE-2026-34453?
- CVE-2026-34453 is a high-severity vulnerability in B3log Siyuan, classified under Incorrect Authorization. CVSS score: 7.5/10. Published 2026-03-31.
- How severe is CVE-2026-34453?
- High severity. CVSS v3 base score is 7.5 out of 10.