XSS in Siyuan-Note Siyuan

CVE-2026-65606

SiYuan before v3.7.2 contains a cross-site scripting vulnerability in the siyuan:// protocol handler. When a siyuan://plugins/<name> link references a name that is not an installed plugin, the application opens a custom tab and inserts the link's icon parameter into the tab header via innerHTML without escaping it (app/src/layout/Tab.ts), allowing injection of an <img onerror=...> element. Because the SiYuan Desktop renderer runs with nodeIntegration:true, the injected JavaScript can access Node's require and call require('child_process').execSync(...), escalating the cross-site scripting into arbitrary operating-system 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-2026-65606: 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-2026-65606?
CVE-2026-65606 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-2026-65606?
Critical severity. CVSS v3 base score is 9.6 out of 10.