CVE-2026-74798: siyuan-note siyuan Path Traversal

Vulnerability summary

CVE-2026-74798 is a critical (CVSS 9.3) Path Traversal vulnerability in siyuan-note siyuan. EPSS estimates a 0.51% chance of exploitation in the next 30 days, higher than 41.9% of scored vulnerabilities.

Timeline

1. 17-08-2026
   PublishedVulnerability first disclosed.
2. 18-08-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.