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)

Published · last modified .

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.

EPSS exploit prediction

EPSS: 0.008 (55.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 55.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-65605: held from 0.006 to 0.008.

EPSS over last 30 days · oldest: 0.006 · newest: 0.008 · change: +0.001

Affected products

Weakness classification (CWE)

References

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.