CVE-2026-39846 CRITICAL

CVE-2026-39846: SiYuan affected by Remote Code Execution in the Electron desktop client via stored XSS in synced table captions

Vendor Siyuan-Note
Product siyuan
Weakness CWE-79 · XSS
Published April 7, 2026
Last update April 8, 2026

CVSS base score

9.1/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction Required
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H

What the vulnerability does

01Description

SiYuan is a personal knowledge management system. Prior to 3.6.4, a malicious note synced to another user can trigger remote code execution in the SiYuan Electron desktop client. The root cause is that table caption content is stored without safe escaping and later unescaped into rendered HTML, creating a stored XSS sink. Because the desktop renderer runs with nodeIntegration enabled and contextIsolation disabled, attacker-controlled JavaScript executes with access to Node.js APIs. In practice, an attacker can import a crafted note into a synced workspace, wait for the victim to sync, and achieve code execution when the victim opens the note. This vulnerability is fixed in 3.6.4.

Key dates

02Disclosure timeline

April 7, 2026 CVE published
April 8, 2026 Record updated