CVE-2026-102673: Electron drops inherited HTML sandbox restrictions for popups opened through OpenURLFromTab

Severity: medium (CVSS 6.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-29 · updated 2026-10-15
Weakness: CWE-346

Description

Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 41.10.4, 42.5.2, and 43.0.0, popups opened from a sandboxed iframe through Electron's OpenURLFromTab navigation path, including links using target="_blank" or a middle-click, did not receive the inherited HTML sandbox restrictions. An untrusted iframe using the allow-scripts allow-popups configuration could therefore open a popup with the embedding application's full origin, exposing that origin's cookies, storage, and same-origin scripting capabilities. Applications that do not embed untrusted content in sandboxed iframes are not affected. This issue is fixed in versions 41.10.4, 42.5.2, and 43.0.0.

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

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