CVE-2026-100643 SiYuan before v3.8.4 Stored XSS via Attribute View textarea
Authenticated attackers can inject JavaScript via Attribute View fields, leading to command execution in the Electron desktop app when nodeIntegration is enabled.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-100643?
CVE-2026-100643 is a high-severity cross-site scripting vulnerability in siyuan-note siyuan, published on 26 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
SiYuan versions before v3.8.4 fail to properly escape four stored Attribute View values in textarea elements, allowing authenticated attackers to inject JavaScript by modifying field descriptions, template sources, select option descriptions, or footer calculation templates. Attackers can execute stored JavaScript when other users open affected database menus, and in the Electron desktop app with nodeIntegration enabled, this leads to command execution with SiYuan process privileges.
Weakness: CWE-79
Which versions are affected by CVE-2026-100643?
How do I fix CVE-2026-100643?
No fix has been published for CVE-2026-100643 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-100643 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-100643 exists.
Sources
Also known as GHSA-3pv4-cp72-vhj4, GHSA-h3p6-c22r-fx2j.