CVE-2026-100636
SiYuan versions before v3.8.4 contain a path traversal vulnerability in the exportBrowserHTML endpoint that allows authenticated administrators to write arbitrary HTML content to index.html outside the workspace directory. Attackers can supply a folder parameter with directory traversal sequences to escape the export directory and overwrite index.html in any pre-existing kernel-writable location, enabling stored XSS or workspace defacement.
- Published Sep 26, 2026
- CVSS 8.3 high
- 0.5% chance of exploitation in the next 30 days (EPSS)
- A fix is available