CVE-2026-65606

9.4 CRITICAL 0.8% exploit odds Fix listed XSS Web app

What it is

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.

At a glance

Exploitability: Can be exploited over the network without logging in, but needs a user to act. High risk of data exposure, data tampering, service disruption.
Exploit odds: 0.8% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-07-23 12:18 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-09-17 18:17 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.8% in the next 30 days (EPSS).
Severity: 9.4 CRITICAL (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-07-23 12:18 UTC
Last modified: 2026-09-17 18:17 UTC
Exploit probability: 0.8% · EPSS, next 30 days
Weakness: CWE-79 · Cross-site scripting
Record status: Deferred

Attack profile CVSS 4.0 · 9.4

Attack vector: Network
Complexity: Low
Attack requirements: None
Privileges needed: None
User interaction: Passive
Confidentiality: High
Integrity: High
Availability: High

Raw vector

CVSS: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

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-65606.md and follow it. Check whether this project is affected by CVE-2026-65606. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record