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)
EPSS: 0.002 (10.6th percentile) — read the EPSS interpretation.
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.
Affected products
- B3log Siyuan — versions 3.5.4
- Siyuan-note Siyuan — versions < 3.5.5
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
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.