CVE-2026-74798 SiYuan kernel Path Traversal via database_clean MCP tool
An authenticated attacker can exploit a path traversal flaw in the MCP tool to read and delete arbitrary files on the host system.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-74798?
CVE-2026-74798 is a critical path traversal vulnerability in siyuan-note siyuan, published on 17 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.
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.
Weakness: CWE-22
Which versions are affected by CVE-2026-74798?
How do I fix CVE-2026-74798?
No fix has been published for CVE-2026-74798 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-74798 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-74798 exists.
Sources
Also known as GHSA-mwfp-66vr-j373.