CVE-2026-102673

Impact

Popups opened from a sandboxed iframe through a link (for example target="_blank" or a middle-click) did not inherit the iframe's HTML sandbox restrictions. Content that was meant to run sandboxed could open a popup with the embedding app's full origin, gaining access to that origin's cookies, storage, and same-origin scripting.

Apps are only affected if they embed untrusted content in iframes sandboxed with allow-scripts allow-popups. Apps that do not embed untrusted content in sandboxed iframes are not affected.

Workarounds

Use setWindowOpenHandler on the parent WebContents to deny or constrain popups opened from sandboxed frames, or do not apply allow-popups to sandboxed iframes that render untrusted content.

Fixed Versions

• 43.0.0
• 42.5.2
• 41.10.4

For more information

If you have any questions or comments about this advisory, email us at security@electronjs.org