CVE-2026-40318: b3log Siyuan

High severity, CVSS 8.5. EPSS: 0.4% chance of exploitation in the next 30 days.

SiYuan is an open-source personal knowledge management system. In versions 3.6.3 and prior, the /api/av/removeUnusedAttributeView endpoint constructs a filesystem path using the user-controlled id parameter without validation or path boundary enforcement. An attacker can inject path traversal sequences such as ../ into the id value to escape the intended directory and delete arbitrary .json files on the server, including global configuration files and workspace metadata. This issue has been fixed in version 3.6.4.

Affected products

• b3log Siyuan: before 3.6.4 (fixed in 3.6.4)

Published 2026-04-16. Last modified 2026-06-17.