XSS in B3log Siyuan
CVE-2026-25647
Lute is a structured Markdown engine supporting Go and JavaScript. Lute 1.7.6 and earlier (as used in SiYuan before) has a Stored Cross-Site Scripting (XSS) vulnerability in the Markdown rendering engine. An attacker can inject malicious JavaScript into a Markdown text/note. When another user clicks the rendered content, the script executes in the context of their session.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.6 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (16.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 16.3% 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
- B3log Siyuan — versions 3.5.4
- Siyuan-Note Siyuan — versions < 3.5.5
Weakness classification (CWE)
References
- github.com/siyuan-note/siyuan/security/advisories/GHSA-rw25-98wq-76qv (Exploit, Vendor Advisory)
- github.com/88250/lute/commit/0118e218916cf0cc7df639b50ce74e0c6c3d1868 (Patch)
Frequently asked questions
- What is CVE-2026-25647?
- CVE-2026-25647 is a medium-severity vulnerability in B3log Siyuan, classified under Cross-site Scripting. CVSS score: 4.6/10. Published 2026-02-06.
- How severe is CVE-2026-25647?
- Medium severity. CVSS v3 base score is 4.6 out of 10.