SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-65606

SiYuan before v3.7.2 contains a cross-site scripting vulnerability in the siyuan:// protocol handler.

CRITICAL 9.4EPSS 0.79%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.79%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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 4.0
9.4 CRITICALCVSS: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/M
EPSS
0.79% probability · 54th percentile
CISA KEV
Not listed
Weakness
CWE-79
Source
disclosure@vulncheck.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.