CVE-2026-100636

Name of the Vulnerable Software and Affected Versions SiYuan versions prior to 3.8.4

Description A path traversal issue exists in the 'exportBrowserHTML' endpoint. Authenticated administrators can use directory traversal sequences in the folder parameter to write arbitrary HTML content to an index.html file outside the workspace directory. This allows the overwriting of index.html in any location writable by the kernel, which can lead to stored Cross-Site Scripting (XSS)—a technique where malicious scripts are permanently stored on the target server—or workspace defacement.

Recommendations Update SiYuan to version 3.8.4 or later. Avoid using the folder parameter in the 'exportBrowserHTML' endpoint until the update is applied.