CVE-2026-41421: siyuan-note siyuan OS Command Injection

Vulnerability summary

CVE-2026-41421 is a high (CVSS 8.8) OS Command Injection vulnerability in siyuan-note siyuan. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 8.9% of scored vulnerabilities.

Timeline

1. 24-04-2026
   PublishedVulnerability first disclosed.
2. 25-04-2026
   Last modifiedVulnerability information updated.

Description

SiYuan is an open-source personal knowledge management system. Prior to 3.6.5, SiYuan desktop renders notification messages as raw HTML inside an Electron renderer. The notification route POST /api/notification/pushMsg accepts a user-controlled msg value, forwards it through the backend broadcast layer, and the frontend inserts it into the DOM with insertAdjacentHTML(...) at message.ts. On desktop builds, this is not limited to ordinary XSS. Electron windows are created with nodeIntegration: true, contextIsolation: false, and webSecurity: false at main.js. As a result, JavaScript executed from the notification sink can directly access Node APIs and escalate to desktop code execution. This vulnerability is fixed in 3.6.5.

• CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.
• CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.