CVE-2026-93923 SiYuan through 3.8.4 Stored XSS via Heading Style Attribute
Attackers can inject malicious scripts via heading styles in SiYuan, leading to code execution in the Electron renderer.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-93923?
CVE-2026-93923 is a high-severity cross-site scripting vulnerability in siyuan-note siyuan, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
SiYuan through 3.8.4 fails to escape heading style attributes when rendering outline and bookmark dock HTML, allowing stored cross-site scripting. Attackers can supply crafted notebooks or call administrative endpoints to inject malicious style values that execute in the Electron renderer with full system access.
Weakness: CWE-79
Which versions are affected by CVE-2026-93923?
How do I fix CVE-2026-93923?
No fix has been published for CVE-2026-93923 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-2026-93923 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-93923 exists.
Sources
Also known as GHSA-928g-4hfq-qwvx, GHSA-qvp6-cjg5-8753.