CVE-2026-70607: Electron: window.open features string controls some window options considered privileged

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% 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-20

Description

Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 39.8.8, 40.9.0, 41.2.1, and 42.0.0-beta.3, some window options supplied by web content in the window.open() features string were applied to the new BrowserWindow without an allowlist. Untrusted content could set window options it should not control, including options that cause the main process to access attacker-chosen file or network paths, when untrusted content can call window.open() and the app does not override child window options via setWindowOpenHandler or overrideBrowserWindowOptions. This issue is fixed in 39.8.8, 40.9.0, 41.2.1, and 42.0.0-beta.3.

Affected products

electron: before 39.8.8; from 40.0.0 before 40.9.0; from 41.0.0 through 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 39.8.8, 40.9.0

How to fix

Upgrade to a fixed version: electron 39.8.8, 40.9.0. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-70607 or the next vulnerability affects your stack