CVE-2026-100636 SiYuan before v3.8.4 Path Traversal via exportBrowserHTML folder
Authenticated administrators can exploit path traversal in the export endpoint to overwrite files, enabling stored XSS or defacement.
- 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-2026-100636?
CVE-2026-100636 is a high-severity path traversal vulnerability in siyuan-note siyuan, published on 26 Sep 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
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.
Weakness: CWE-22
Which versions are affected by CVE-2026-100636?
How do I fix CVE-2026-100636?
No fix has been published for CVE-2026-100636 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-2026-100636 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-100636 exists.
Sources
Also known as GHSA-jf98-m24w-gm9m, GHSA-mcx7-cgpm-84c8.