siyuan-note SiYuan 3.7.0/3.8.9 Web Fetch kernel/util/webfetch.go path traversal

Summaryinfo

A vulnerability, which was classified as problematic, was found in siyuan-note SiYuan 3.7.0/3.8.9. Affected is an unknown function of the file kernel/util/webfetch.go of the component Web Fetch. Such manipulation leads to path traversal. This vulnerability is uniquely identified as CVE-2026-126776. The attack can be launched remotely. No exploit exists. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in siyuan-note SiYuan 3.7.0/3.8.9. Affected by this issue is some unknown functionality of the file kernel/util/webfetch.go of the component Web Fetch. The manipulation with an unknown input leads to a path traversal vulnerability. Using CWE to declare the problem leads to CWE-22. 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. Impacted is integrity. CVE summarizes:

SiYuan 3.7.0 before 3.8.10 on Windows contains a path traversal vulnerability in kernel/util/webfetch.go that allows attackers to write files outside the import directory via backslash-encoded filenames. Attackers controlling a URL fetched by the MCP web_fetch or http_request tools can use %5C-encoded ..\ sequences to write chosen response bytes to directories above temp/import that are writable by the SiYuan user.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-126776 since 11/11/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1006 by the MITRE ATT&CK project.

Upgrading to version 3.8.10 eliminates this vulnerability.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

• siyuan-note

Name

• SiYuan

Version

• 3.7.0
• 3.8.9

Website

• Product: https://github.com/siyuan-note/siyuan/

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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