CVE-2026-65606: SiYuan before v3.7.2 Cross-Site Scripting to RCE
Vulnerability summary
CVE-2026-65606 is a critical (CVSS 9.6) Cross-site Scripting vulnerability in siyuan-note siyuan. EPSS estimates a 0.79% chance of exploitation in the next 30 days, higher than 55.7% of scored vulnerabilities.
Timeline
- 23-07-2026PublishedVulnerability first disclosed.
- 17-09-2026Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
4 scores · 2 sources · 2 versions- NVDNIST9.4CriticalCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- NVDNIST9.6CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
EPSS trend
Probability
0.79%
Chance of exploitation in the next 30 days
Percentile
56%
Versus all other CVEs
30-day change
Increase +0.14 pp
From 0.65% on 22-09-2026
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Siyuan-note1 product
- siyuan< 3.7.2
1 vendor · 1 product
References
3 links- www.vulncheck.com/advisories/siyuan-before-cross-site-scripting-to-rceThird Party Advisory