Which versions of SiYuan are affected by EUVD-2026-38163?

SiYuan note-taking application versions before 3.6.1 contain a critical remote code execution vulnerability in its Bazaar marketplace package handler, allowing attackers who publish packages to…. A patch is available.

Is there a public PoC exploit available for EUVD-2026-38163?

Yes, a public proof-of-concept exploit is available for EUVD-2026-38163. Prioritise patching immediately. EPSS: 0.4%.

How to fix or mitigate EUVD-2026-38163?

Within 24 hours: inventory all SiYuan deployments and document running versions across the organization. Within 7 days: deploy SiYuan v3.6.1 or later to all endpoints and audit installed marketplace packages for suspicious authors or modification dates. Within 30 days: implement marketplace package approval workflow and configure endpoint monitoring to alert on SiYuan child process spawning.

SiYuan EUVD-2026-38163

Q: What is the CVSS score of EUVD-2026-38163?

EUVD-2026-38163 has a CVSS 4.0 base score of 9.4 (Critical). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.4%.

| CVE-2026-56397 CRITICAL

Cross-site Scripting (XSS) (CWE-79)

2026-06-21 VulnCheck

GHSA-24r3-p3x6-cqvx

XSS RCE Siyuan

9.4

CVSS 4.0 · Vendor: VulnCheck

Severity by source

Vendor (VulnCheck) PRIMARY

9.4 CRITICAL

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

vuln.today AI

9.6 CRITICAL

Network-reachable Bazaar listing, no attacker auth, victim must open Bazaar (UI:R); Electron nodeIntegration escapes the renderer sandbox to the host OS, so Scope:Changed with full C/I/A impact.

3.1 AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

4.0 AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

Primary rating from Vendor (VulnCheck).

CVSS VectorVendor: VulnCheck

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Scope

Lifecycle Timeline

Source Code Evidence Fetched

Jun 22, 2026 - 07:50 vuln.today

Analysis Generated

Jun 22, 2026 - 07:50 vuln.today

Patch available

Jun 21, 2026 - 15:31 EUVD

DescriptionCVE.org

SiYuan before v3.6.1 fails to sanitize package metadata and README content in the Bazaar marketplace, allowing malicious package authors to inject arbitrary HTML and JavaScript. Attackers can achieve remote code execution on any user browsing the Bazaar by embedding XSS payloads in package displayName, description, or README fields, exploiting Electron's nodeIntegration setting to execute OS commands.

AnalysisAI

Remote code execution in SiYuan note-taking application (before v3.6.1) allows any malicious Bazaar marketplace package author to compromise users via unsanitized HTML rendering of package displayName, description, and README content. Because the Electron renderer is configured with nodeIntegration:true and contextIsolation:false, injected JavaScript pivots directly to arbitrary OS command execution. No public exploit identified at time of analysis, but VulnCheck published a detailed technical advisory documenting both zero-click (metadata) and one-click (README) vectors.

Technical ContextAI

SiYuan is a self-hosted Electron-based personal knowledge management application with a built-in community marketplace called the Bazaar that distributes plugins, themes, and templates. The flaw is a classic CWE-79 (Improper Neutralization of Input During Web Page Generation) with two distinct sinks: (1) in app/src/config/bazaar.ts:275-277, package preferredName and preferredDesc fields are interpolated directly into HTML template literals without escaping, while only the title attribute uses escapeAttr(); (2) in kernel/bazaar/package.go:635-645, renderREADME() invokes lute.New() without calling SetSanitize(true), so raw HTML embedded in package README markdown is preserved by Md2HTML() and assigned via innerHTML on the frontend - inconsistent with the note renderer at kernel/util/lute.go:81 which does sanitize. The impact is amplified because app/electron/main.js:422-426 enables nodeIntegration:true and contextIsolation:false, granting any executed script access to Node.js APIs such as child_process. Affected CPE is cpe:2.3:a:siyuan:siyuan:*:*:*:*:*:*:*:*.

RemediationAI

Upgrade SiYuan to v3.6.1 or later, which the vendor advisory GHSA-v3mg-9v85-fcm7 identifies as the fixed release containing HTML escaping for Bazaar metadata fields and SetSanitize(true) on the README Lute engine. If immediate upgrade is not possible, the most effective compensating control is to avoid opening the Bazaar marketplace UI entirely until patched, since both vectors require rendering the marketplace listing; advise users not to install, preview, or browse community packages. A stronger architectural mitigation - disabling nodeIntegration and enabling contextIsolation in app/electron/main.js - would prevent OS command execution but requires code changes and may break legitimate plugins that depend on Node APIs, so it is impractical as a temporary workaround. Network-level blocking of the Bazaar CDN (cdn.jsdelivr.net/gh/siyuan-note) prevents listing fetches but also breaks legitimate marketplace functionality.