CVE-2026-55570 Cross-site scripting in siyuan
Attackers can execute arbitrary OS commands via stored XSS in the SiYuan marketplace due to unescaped attributes in the desktop client.
- 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-2026-55570?
CVE-2026-55570 is a critical cross-site scripting vulnerability in siyuan-note siyuan, published on 24 Jun 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 is an open-source personal knowledge management system. Prior to 3.7.0, it does not escape the untrusted fields (name, version, author, description) when they are serialized into the data-obj HTML attribute of each marketplace card. Because the attribute is single-quoted and the value is produced with JSON.stringify() (which does not escape ', <, or >), a package whose name contains a single quote breaks out of the attribute and injects arbitrary HTML. In the desktop client the main BrowserWindow runs with nodeIntegration: true, contextIsolation: false, so the injected markup escalates from DOM XSS to arbitrary OS command execution. This is the same root cause and same impact as the original advisory, reached through a sibling sink the patch did not cover. This vulnerability is fixed in 3.7.0.
Which versions are affected by CVE-2026-55570?
How do I fix CVE-2026-55570?
No fix has been published for CVE-2026-55570 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-2026-55570 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55570 exists.
Sources
Also known as GHSA-x88j-wgpr-h22x.