CVE-2026-70599: Electron: Permission Check Handler Receives Main Frame Origin Instead of Requesting Iframe Origin

Severity: medium (CVSS 5.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-05 · updated 2026-10-08
Weakness: CWE-346

Description

Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 39.8.7, 40.9.0, 41.2.0, and 42.0.0-beta.1, serial-port and media permission checks made from an iframe passed the top-level frame origin to session.setPermissionCheckHandler instead of the requesting iframe origin. Origin-based handler logic could grant a cross-origin iframe device access intended only for the top-level origin. This issue is fixed in 39.8.7, 40.9.0, 41.2.0, and 42.0.0-beta.1.

Affected products

electron: before 39.8.7; from 40.0.0 before 40.9.0; from 41.0.0 before 41.2.1; 42.0.0-alpha1, 42.0.0-alpha2, 42.0.0-alpha3, 42.0.0-alpha4, 42.0.0-alpha5, 42.0.0-alpha6 (+2) — fixed in 39.8.7, 40.9.0, 41.2.1

How to fix

Upgrade to a fixed version: electron 39.8.7, 40.9.0, 41.2.1. Check the vendor advisory for mitigations.

References

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