CVE-2026-87814 SiYuan before v3.8.2 Stored XSS via Asset Preview
Attackers can execute JavaScript in SiYuan via stored XSS in asset previews, enabling API requests and workspace manipulation.
- 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-2026-87814?
CVE-2026-87814 is a high-severity cross-site scripting vulnerability in siyuan-note siyuan, published on 9 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 before v3.8.2 contains a stored cross-site scripting vulnerability in the search asset preview feature that fails to escape indexed asset content before inserting it into the DOM using innerHTML. Attackers who can place crafted text assets in a workspace can execute JavaScript in the SiYuan origin when victims preview the assets, enabling authenticated API requests and workspace manipulation.
Weakness: CWE-79
Which versions are affected by CVE-2026-87814?
How do I fix CVE-2026-87814?
No fix has been published for CVE-2026-87814 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-2026-87814 being exploited?
There is no known exploitation of CVE-2026-87814 in the wild and no public exploit code.
Sources
Also known as GHSA-64gp-333q-mq6j, GHSA-gxwj-6x5p-v77c.