GHSA-9f4c-93c8-jc8g

Electron: Sandboxed iframe can bypass the allow-popups restriction via the OpenURL navigation path

### Impact A sandboxed iframe without the `allow-popups` keyword could still open a new window (or trigger `setWindowOpenHandler`) with no user interaction, because new-window navigations taking the OpenURL path did not apply the iframe sandbox popup restriction. Apps that embed untrusted content in sandboxed iframes and rely on the absence of `allow-popups` to prevent window creation are affected. Apps that deny window creation in `setWindowOpenHandler`, or that do not embed untrusted content in sandboxed iframes, are not affected. ### Workarounds Return `{ action: 'deny' }` from `setWindowOpenHandler` for any content you do not trust, rather than relying on the iframe sandbox alone. ### Fixed Versions * `42.0.1` * `41.10.3` * `39.8.10` ### For more information If you have any questions or comments about this advisory, email Electron at [security@electronjs.org](mailto:security@electronjs.org)