Is this vulnerability remotely exploitable, or does the attacker need local access?

It is remotely exploitable in the sense that an attacker only needs a path to sync or import a malicious note into the victim's workspace; they do not require local shell or direct file system access on the victim's machine.

What level of access does an attacker need to exploit this issue?

The attacker needs the ability to influence note content that the victim's desktop client will render—through a shared workspace, compromised sync channel, or a crafted note that the victim imports. No direct access to the victim's machine is required beyond this content injection path.

What is the safest general fix pattern for this class of vulnerability?

The safest pattern is to ensure robust output encoding and/or sanitization for all user-controlled content before rendering to HTML, combined with hardened Electron settings: disable nodeIntegration, enable contextIsolation, and strictly control any IPC bridges so that renderer scripts cannot directly access system-level APIs.

Severity:

CRITICAL RISK

(9.0)

Stored XSS to Remote Code Execution (CWE-79) in SiYuan Electron Desktop Client

CVE-2026-39846

Published:

Apr 7, 2026

Status:

Analyzed

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

NDV

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May 10, 2026

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HIGH RISK

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May 10, 2026

Vulnerability Type

Category:

Stored Cross-Site Scripting (XSS)

CWE:

CWE-79;CWE-94

Impact:

Remote Code Execution via Stored XSS in Desktop Client

Severity:

CRITICAL RISK

(9.0)

CVSS Version:

3.1

Vulnerability Type

Category:

Stored Cross-Site Scripting (XSS)

CWE:

CWE-79;CWE-94

Impact:

Remote Code Execution via Stored XSS in Desktop Client

Severity:

CRITICAL RISK

(9.0)

CVSS Version:

3.1

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Stored XSS to Remote Code Execution (CWE-79) in SiYuan Electron Desktop Client

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

Recent Vulnerabilities

HIGH RISK

HIGH

(8.8)

PHP Code Injection via File Upload (CWE-94) in Aero CMS Admin Post Creation

HIGH RISK

HIGH

(8.8)

Code Injection (CWE-94) via Module Parameters in Evolution CMS

Vulnerability Type

Vulnerability Type

Vulnerability Type

Catch This CVE While Code Is Being Written

Ship clean & secure code faster

Ship clean & secure code faster

Ship clean & secure code faster

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