CVE-2026-33067: b3log Siyuan

Critical severity, CVSS 9.0. EPSS: 0.7% chance of exploitation in the next 30 days.

SiYuan is a personal knowledge management system. Versions 3.6.0 and below render package metadata fields (displayName, description) using template literals without HTML escaping. A malicious package author can inject arbitrary HTML/JavaScript into these fields, which executes automatically when any user browses the Bazaar page. Because SiYuan's Electron configuration enables nodeIntegration: true with contextIsolation: false, this XSS escalates directly to full Remote Code Execution on the victim's operating system — with zero user interaction beyond opening the marketplace tab. This issue has been fixed in version 3.6.1.

Affected products

• b3log Siyuan: before 3.6.1 (fixed in 3.6.1)

Published 2026-03-20. Last modified 2026-06-17.