# CVE-2026-116168: SiYuan path traversal in MCP asset tool via incomplete blacklist

Source: https://junglewise.ai/threats/cve-2026-116168-siyuan-before-3-8-7-contains-a-path-traversal-vulnerability-in  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-25. Updated: 2026-10-25  
License: CC BY 4.0 with a link back

CVE-2026-116168 · Severity: medium · CVSS 6.2 · Published 2026-10-25

SiYuan is a note-taking application that supports integration with AI agents through an MCP (Model Context Protocol) server. An incomplete security filter in the asset upload feature allows authenticated agents to read sensitive local files like .env from the host system by uploading them into the workspace and then downloading them via HTTP, potentially exposing API keys and credentials.

Technologies: [SiYuan Note SiYuan](https://junglewise.ai/threats/technologies/siyuan-note-siyuan). Vendors: [SiYuan Note](https://junglewise.ai/threats/vendors/siyuan-note).

## Quick answers

**Is CVE-2026-116168 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-116168 being exploited in the wild.

**How severe is CVE-2026-116168?** Medium severity, with a CVSS score of 6.2, published 25 October 2026.

**Which products and versions are affected?** SiYuan Note SiYuan before 3.8.7.

**Is there a fix for CVE-2026-116168?** Yes: fixed in 3.8.7. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-116168 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-116168?** Check whether you run SiYuan Note SiYuan at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 3.8.7

## Technical details

The validateAssetUploadPaths function in the MCP asset tool uses an incomplete blacklist (isSensitivePath) to block uploads of sensitive files. The blacklist omits .env and .env.* files from its 17-entry dotfile list, allowing authenticated attackers to invoke the asset upload action with paths like /home/user/.env, copy the file into the workspace, and exfiltrate it via the /assets/ HTTP endpoint. This is a path traversal vulnerability (CWE-22) requiring MCP server access and an active agent principal but no additional filesystem privileges.

## Affected products

- siyuan-note SiYuan before 3.8.7

## Timeline

- 2026-10-09: disclosed
- 2026-10-25: advisory
- 2026-10-25: patched

## References

- [https://github.com/siyuan-note/siyuan/security/advisories/GHSA-q768-4j87-gf3w](https://github.com/siyuan-note/siyuan/security/advisories/GHSA-q768-4j87-gf3w)
- [https://www.vulncheck.com/advisories/siyuan-before-3.8.7-path-traversal-local-file-read-via-mcp-asset-tool](https://www.vulncheck.com/advisories/siyuan-before-3.8.7-path-traversal-local-file-read-via-mcp-asset-tool)

## Related threats

- [SiYuan path-traversal bypass via Windows extended-length prefix](https://junglewise.ai/threats/cve-2026-116171-siyuan-3-5-4-before-3-8-7-on-windows-contains-a-sensitive-path)
- [SiYuan stored cross-site scripting in KaTeX math blocks](https://junglewise.ai/threats/cve-2026-116169-siyuan-from-2-10-0-before-3-8-7-contains-a-stored-cross-site)
- [SiYuan getAttributeViewSearchTarget insufficient access control](https://junglewise.ai/threats/go-2026-6632-siyuan-getattributeviewsearchtarget-returns-database-row-fd3e0f1a)
- [SiYuan Cross-Site WebSocket Hijacking in network proxy endpoint](https://junglewise.ai/threats/cve-2026-74802-siyuan-cross-site-websocket-hijacking-on-the-admin-only-network)
- [SiYuan missing authorization in save-path resolver endpoints](https://junglewise.ai/threats/cve-2026-103762-siyuan-before-v3-8-5-contains-a-missing-authorization)