Executive brief
SiYuan is a personal knowledge management system used for organizing notes and data. A security flaw in the desktop application allows a malicious user to create a specially crafted note that, when shared or synced and opened by another user, can take full control of the victim's computer. This could result in the theft of sensitive personal data, installation of malware, or complete loss of system access.
Technical details
A stored Cross-Site Scripting (XSS) vulnerability exists in the SiYuan Electron desktop client due to improper neutralization of table caption content. The application stores table captions without escaping and subsequently unescapes them into the rendered HTML DOM. Because the Electron renderer is configured with 'nodeIntegration' enabled and 'contextIsolation' disabled, an attacker can leverage this XSS sink to execute arbitrary Node.js APIs, such as 'child_process.exec'. The attack is delivered by importing a crafted '.sy.zip' note into a shared workspace; when a victim syncs and opens the note, the payload executes in the context of the logged-in user. This issue is resolved in version 3.6.4.
Affected products
- siyuan-note SiYuan < 3.6.4
Timeline
- 2026-04-07: disclosed
- 2026-04-07: advisory
- 2026-04-07: patched: Fixed in version 3.6.4