XSS in Siyuan-Note Siyuan
CVE-2026-65605
SiYuan before v3.7.2 contains a stored cross-site scripting vulnerability in Attribute View (database) cell rendering. A Template column value is rendered as HTML via text/template without auto-escaping, and EscapeHTML is only applied when HasUnclosedHtmlTag returns true; because balanced self-closing tags such as <img> are skipped by that check, a payload like <img src=x onerror=...> is stored unescaped and later inserted into the page via innerHTML, executing when the database is viewed. Because the desktop renderer runs with nodeIntegration enabled, the injected script can reach require and escalate to arbitrary command execution.
Vulnerability class: XSS (Cross-Site Scripting)
EPSS: 0.008 (53.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H.
Affected products
- Siyuan-note Siyuan — versions 0, 3.7.2
Weakness classification (CWE)
References
- disclosure@vulncheck.com (patch)
- disclosure@vulncheck.com (vendor-advisory)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2026-65605?
- CVE-2026-65605 is a critical-severity vulnerability in Siyuan-Note Siyuan, classified under Cross-site Scripting. CVSS score: 9.6/10. Published 2026-07-23.
- How severe is CVE-2026-65605?
- Critical severity. CVSS v3 base score is 9.6 out of 10.