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Electron: Renderer command-line switch injection via undocumented commandLineSwitches webPreference

High severity GitHub Reviewed Published Apr 2, 2026 in electron/electron • Updated Apr 6, 2026

Package

npm electron (npm)

Affected versions

< 38.8.6
>= 39.0.0-alpha.1, < 39.8.0
>= 40.0.0-alpha.1, < 40.7.0
>= 41.0.0-alpha.1, < 41.0.0-beta.8

Patched versions

38.8.6
39.8.0
40.7.0
41.0.0-beta.8

Description

Impact

An undocumented commandLineSwitches webPreference allowed arbitrary switches to be appended to the renderer process command line. Apps that construct webPreferences by spreading untrusted configuration objects may inadvertently allow an attacker to inject switches that disable renderer sandboxing or web security controls.

Apps are only affected if they construct webPreferences from external or untrusted input without an allowlist. Apps that use a fixed, hardcoded webPreferences object are not affected.

Workarounds

Do not spread untrusted input into webPreferences. Use an explicit allowlist of permitted preference keys when constructing BrowserWindow or webContents options from external configuration.

Fixed Versions

  • 41.0.0-beta.8
  • 40.7.0
  • 39.8.0
  • 38.8.6

For more information

If there are any questions or comments about this advisory, send an email to security@electronjs.org

References

@VerteDinde VerteDinde published to electron/electron Apr 2, 2026
Published to the GitHub Advisory Database Apr 3, 2026
Reviewed Apr 3, 2026
Published by the National Vulnerability Database Apr 4, 2026
Last updated Apr 6, 2026

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Local
Attack complexity
High
Privileges required
None
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(14th percentile)

Weaknesses

Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')

The product constructs a string for a command to be executed by a separate component in another control sphere, but it does not properly delimit the intended arguments, options, or switches within that command string. Learn more on MITRE.

Hidden Functionality

The product contains functionality that is not documented, not part of the specification, and not accessible through an interface or command sequence that is obvious to the product's users or administrators. Learn more on MITRE.

CVE ID

CVE-2026-34769

GHSA ID

GHSA-9wfr-w7mm-pc7f

Source code

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