Which versions of SiYuan are affected by CVE-2026-59855?

SiYuan knowledge management tool (versions before 3.7.1) enables remote code execution on user machines through a cross-site scripting flaw in asset handling.

How to fix or mitigate CVE-2026-59855?

Within 24 hours: Identify all SiYuan deployments and notify users to avoid opening asset links from external sources. Within 7 days: Assess criticality of SiYuan to business operations; if non-essential, disable on production and high-value systems pending patch release. Within 30 days: Subscribe to SiYuan release notifications and prepare deployment of patched version 3.7.1 or later once released; track vendor advisory for patch availability.

SiYuan CVE-2026-59855

Q: What is the CVSS score of CVE-2026-59855?

CVE-2026-59855 has a CVSS 4.0 base score of 8.6 (High). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/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: 0.3%.

HIGH

Basic XSS (CWE-80)

2026-07-09 GitHub_M

XSS Siyuan Siyuan Note

8.6

CVSS 4.0 · Vendor: GitHub_M

Severity by source

Vendor (GitHub_M) PRIMARY

8.6 HIGH

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

8.8 HIGH

Remotely deliverable content but requires the victim to open the crafted asset (UI:R); no attacker privileges (PR:N); Electron renderer RCE yields high C/I/A; scope unchanged as impact stays within the app's OS context.

3.1 AV:N/AC:L/PR:N/UI:R/S:U/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:N/SI:N/SA:N

Primary rating from Vendor (GitHub_M).

CVSS VectorVendor: GitHub_M

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Scope

Lifecycle Timeline

Analysis Generated

Jul 09, 2026 - 23:23 vuln.today

DescriptionCVE.org

SiYuan is an open-source personal knowledge management system. Prior to 3.7.1, Asset.render in app/src/asset/index.ts interpolates the unsanitized this.path value into HTML assigned to innerHTML, allowing a crafted asset link containing a double quote to break out of the src attribute, inject an event handler, and execute JavaScript that can run OS commands in the Electron renderer. This issue is fixed in versions 3.7.1-alpha.2 and 3.7.1.

AnalysisAI

Cross-site scripting escalating to remote code execution in SiYuan (open-source personal knowledge management) before 3.7.1 lets an attacker embed a crafted asset link whose path contains a double quote, breaking out of an image src attribute in Asset.render to inject an event handler. Because SiYuan runs in an Electron renderer with OS-level capabilities, the injected JavaScript can execute arbitrary operating-system commands on the victim's machine once the malicious asset is opened. No public exploit identified at time of analysis, and it is not listed in CISA KEV; user interaction is required to trigger the flaw.

Technical ContextAI

SiYuan is an Electron-based desktop knowledge-management application; the vulnerable code is Asset.render in app/src/asset/index.ts, which builds an HTML string by interpolating the unsanitized this.path property directly into markup that is then assigned to innerHTML. This maps to CWE-80 (Improper Neutralization of Script-Related HTML Tags), a stored/DOM XSS class where attacker-controlled data is written into the DOM without escaping quotes or angle brackets. In a browser this yields ordinary XSS, but in an Electron renderer with Node/OS integration the executing JavaScript can reach OS command execution, turning a markup-injection bug into full RCE. The single affected component per CPE is cpe:2.3:a:siyuan-note:siyuan (all versions prior to the fix).

RemediationAI

Vendor-released patch: upgrade to SiYuan 3.7.1 (or 3.7.1-alpha.2), which sanitizes the asset path before it is written to innerHTML; the fix is commit efbe3a557720034782643e55c9e0282530cb6bbb (https://github.com/siyuan-note/siyuan/commit/efbe3a557720034782643e55c9e0282530cb6bbb) and is described in advisory GHSA-w3gq-5j72-36vc. Until upgrading, avoid opening or importing documents and asset links from untrusted or shared sources, since the malicious payload travels inside asset paths; treat imported .sy documents and shared workspaces as untrusted input. As a defense-in-depth measure, run SiYuan under a restricted OS account to limit the blast radius of renderer-to-OS command execution, accepting the trade-off that this does not prevent data theft from the workspace itself.