Vulnerability · Published Aug 17, 2026 · Assigned by VulnCheck

CVE-2026-74798SiYuan kernel Path Traversal via database_clean MCP tool

High 8.7

In plain English

A high-severity path traversal in siyuan from siyuan-note. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 43% of all known vulnerabilities).

Severity (CVSS 3.1)8.7High

Exploit odds (30 days)0.5%top 56.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
siyuan-note	siyuan	0 – before 3.7.4

Weakness: CWE-22 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N

References

GitHub Security Advisory (GHSA-43jx-gxq4-jpjc) vendor-advisory
VulnCheck Advisory: SiYuan kernel Path Traversal via database_clean MCP tool third-party-advisory