CVE-2026-74798: Siyuan-Note Siyuan

High severity, CVSS 8.7. EPSS: 0.5% chance of exploitation in the next 30 days.

SiYuan kernel before v3.7.4 contains a path traversal vulnerability in the database_clean MCP tool. The tool performs only an empty-string check on the id parameter before passing it to RemoveUnusedAttributeView (kernel/model/attribute_view.go), which builds a filesystem path via filepath.Join without validating that id matches SiYuan's node-ID format. An authenticated MCP client can supply path traversal sequences in id to cause the kernel to copy an arbitrary file readable by the process into SiYuan's history directory (arbitrary file read) and then delete the original file (arbitrary file deletion). The corresponding HTTP API handler was hardened in GHSA-7hm9-v7vf-7g4w, but this MCP caller was not.

Affected products

• Siyuan-Note Siyuan: before 3.7.4 (fixed in 3.7.4)

Published 2026-08-17. Last modified 2026-08-26.