CVE-2026-39846
CRITICALCVE-2026-39846 is a critical-severity (CVSS 9) Cross-site Scripting (XSS) vulnerability in github.com/siyuan-note/siyuan/kernel. O3 Security confirms whether CVE-2026-39846 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
SiYuan affected by Remote Code Execution in the Electron desktop client via stored XSS in synced table captions
Real-World Exposure
github.com/siyuan-note/siyuan/kernelReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/siyuan-note/siyuan/kernel | all versions | 0.0.0-20260407035653-2f416e5253f1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/siyuan-note/siyuan/kernel. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/siyuan-note/siyuan/kernel to 0.0.0-20260407035653-2f416e5253f1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-39846 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-39846 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-39846. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-39846 in your dependencies?
O3 detects CVE-2026-39846 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.