CVE-2026-23645: b3log Siyuan

Medium severity, CVSS 6.1. EPSS: 0.3% chance of exploitation in the next 30 days.

SiYuan is self-hosted, open source personal knowledge management software. Prior to 3.5.4-dev2, a Stored Cross-Site Scripting (XSS) vulnerability exists in SiYuan Note. The application does not sanitize uploaded SVG files. If a user uploads and views a malicious SVG file (e.g., imported from an untrusted source), arbitrary JavaScript code is executed in the context of their authenticated session. This vulnerability is fixed in 3.5.4-dev2.

Affected products

• b3log Siyuan: before 3.5.4 (fixed in 3.5.4); version 3.5.4 only

Published 2026-01-16. Last modified 2026-06-17.