CVE-2026-39846 SiYuan affected by Remote Code Execution in the Electron desktop client via stored XSS in synced table captions
Attackers can achieve remote code execution in the SiYuan desktop client by injecting malicious scripts into synced table captions.
- 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
- Available
What is CVE-2026-39846?
CVE-2026-39846 is a critical cross-site scripting vulnerability in B3log Siyuan, published on 7 Apr 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 a personal knowledge management system. Prior to 3.6.4, a malicious note synced to another user can trigger remote code execution in the SiYuan Electron desktop client. The root cause is that table caption content is stored without safe escaping and later unescaped into rendered HTML, creating a stored XSS sink. Because the desktop renderer runs with nodeIntegration enabled and contextIsolation disabled, attacker-controlled JavaScript executes with access to Node.js APIs. In practice, an attacker can import a crafted note into a synced workspace, wait for the victim to sync, and achieve code execution when the victim opens the note. This vulnerability is fixed in 3.6.4.
Which versions are affected by CVE-2026-39846?
3 open source packages ship an affected version, including github.com/siyuan-note/siyuan/kernel. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/siyuan-note/siyuan/kernel Go | All versions | 0.0.0-20260407035653-2f416e5253f1 |
github.com/siyuan-note/siyuan/kernel Go | All versions | 0.0.0-20260407035653-2f416e5253f1 |
github.com/siyuan-note/siyuan/kernel Go | All versions | 0.0.0-20260407035653-2f416e5253f1 |
Products include B3log Siyuan.
How do I fix CVE-2026-39846?
Upgrade github.com/siyuan-note/siyuan/kernel to 0.0.0-20260407035653-2f416e5253f1 or later.
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-2026-39846 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-39846 exists.
Other vulnerabilities in B3log Siyuan
- CVE-2026-32938 SiYuan has an Arbitrary File Read in its Desktop Publish Service
- CVE-2026-33669 SiYuan has Arbitrary Document Reading within the Publishing Service
- CVE-2026-33670 SiYuan has directory traversal within its publishing service
- CVE-2026-32767 SiYuan: Authorization Bypass Allows Arbitrary SQL Execution via Search API
- CVE-2024-53504 SQL injection in n/a
Sources
Also known as GHSA-phhp-9rm9-6gr2, GO-2026-5540.