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How CVE-2026-70609 Works
Electron is a framework for building cross-platform desktop applications using JavaScript, HTML, and CSS. A vulnerability was identified in the `webContents.openDevTools()` method, specifically in how it handles the `mode` option.
Prior to patched versions (39.8.7, 40.9.0, 41.2.0, and 42.0.0-beta.1), the `mode` option was not sanitized before being passed to the DevTools frontend. If an attacker can influence this `mode` value, they can inject arbitrary JavaScript that executes within the privileged DevTools context.
In unsandboxed Electron configurations, the DevTools context has direct access to Node.js. This means an attacker could leverage the injected script to perform system-level operations such as reading and writing files, spawning child processes, or making network requests. The attack vector is triggered when untrusted input reaches the `mode` argument of `openDevTools()` or when untrusted content calls `openDevTools()` on an embedded `
Applications that only pass a fixed, hardcoded dock mode (e.g., 'right', 'bottom', 'undocked', 'detach') are not affected. The vulnerability is classified under CWE-94 (Code Injection) and CWE-116 (Improper Encoding or Escaping of Output). The CVSS base score is 5.7, indicating a moderate severity.
DailyCVE Form
Platform: Electron
Version: <39.8.7, 40.0.0-alpha.1<40.9.0, 41.0.0-alpha.1<41.2.0, 42.0.0-alpha.1<42.0.0-beta.1
Vulnerability: Code Injection
Severity: Moderate (CVSS 5.7)
date: 2026-08-05
Prediction: 2026-08-05 (Patched)
What Undercode Say: Analytics
The vulnerability stems from improper input sanitization in a core Electron API. The following analytics and commands can be used to assess and verify the vulnerability.
Vulnerable Code Example (Node.js):
const { app, BrowserWindow } = require('electron');
app.whenReady().then(() => {
const win = new BrowserWindow();
win.loadURL('https://example.com');
// Attacker-controlled 'mode' value
const attackerMode = "'; require('child_process').exec('calc.exe'); //";
win.webContents.openDevTools({ mode: attackerMode });
});
Check Current Electron Version:
npm list electron
Update to a Patched Version:
npm install electron@latest or specify a patched version npm install [email protected]
The issue is fixed in versions 42.0.0-beta.1, 41.2.0, 40.9.0, and 39.8.7.
How Exploit:
An attacker can exploit this vulnerability if they can control the `mode` parameter passed to webContents.openDevTools(). This is most likely to occur in applications that:
1. Pass unsanitized user input directly to the `mode` option.
2. Allow untrusted content (e.g., from a third-party website) to call `openDevTools()` on a `
By crafting a malicious string for the `mode` parameter, an attacker can inject JavaScript. For example, the string `’; require(‘child_process’).exec(‘calc.exe’); //` could be used to execute a system command when the DevTools frontend processes it.
Protection:
Update Electron: Immediately update to a patched version: 42.0.0-beta.1, 41.2.0, 40.9.0, or 39.8.7.
Sanitize Input: Never pass untrusted or user-controlled input to the `mode` option of openDevTools().
Use Allowlist: Only pass fixed, allowlisted values (right, bottom, undocked, detach) to the `mode` option.
Restrict Access: Do not expose the `openDevTools()` method to untrusted content, especially within `
Enable Sandbox: Run DevTools in a sandboxed context where possible to limit the impact of a successful injection.
Impact
Code Execution: Arbitrary JavaScript execution in the DevTools context.
System Compromise: In unsandboxed configurations, this grants full Node.js access, leading to potential system-level compromise, including file system access, process manipulation, and network communications.
Privilege Escalation: Attackers can bypass typical security boundaries between frontend JavaScript and system-level operations.
Affected Applications: Primarily impacts applications that process untrusted input for the `mode` argument or allow untrusted content to call `openDevTools()` on a <webview>.
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Sources:
Reported By: github.com
Extra Source Hub:
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