---
title: "CVE-2026-39846: SiYuan: Remote Code Execution in the Electron desktop client via stored XSS in synced table captions"
url: https://erroneo.us/security/cve/CVE-2026-39846/
description: "CVE-2026-39846 (github.com/siyuan-note/siyuan/kernel (Go)): SiYuan is a personal knowledge management system. Prior to 3.6.4, a malicious note synced to…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-04-07
date_modified: 2026-04-08
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-39846"
kev: false
cvss: 9.1
epss: 0.00651
license: All rights reserved. Quote with attribution and a link.
---

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

**Signal:** Critical, preconditions apply. Severe if exploited, but exploitation needs conditions that may not apply to you. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.7% , percentile 51: FIRST’s model estimates a 0.7% chance of exploitation activity in the next 30 days, higher than 51% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes github.com/siyuan-note/siyuan/kernel (Go) < 0.0.0-20260407035653-2f416e5253f1, fixed in 0.0.0-20260407035653-2f416e5253f1 . Check your lockfile, including transitive dependencies.

## What it is

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

- Go `github.com/siyuan-note/siyuan/kernel` < 0.0.0-20260407035653-2f416e5253f1 → fixed: 0.0.0-20260407035653-2f416e5253f1

## Affected products (CVE record)

- siyuan-note siyuan: < 3.6.4

## Severity

- GitHub_M CVSS 3.1: 9.1 `CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.0 `CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.65% probability of exploitation activity in the next 30 days; percentile 51.

## Sources

- [GitHub Advisory GHSA-phhp-9rm9-6gr2](https://github.com/advisories/GHSA-phhp-9rm9-6gr2)
- [CVE.org record CVE-2026-39846](https://www.cve.org/CVERecord?id=CVE-2026-39846)
- [NVD entry CVE-2026-39846](https://nvd.nist.gov/vuln/detail/CVE-2026-39846)
- [github.com](https://github.com/siyuan-note/siyuan/security/advisories/GHSA-phhp-9rm9-6gr2)

---
Source page: https://erroneo.us/security/cve/CVE-2026-39846/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt