Electron: window.open features string controls some window options considered privileged
Package
Affected versions
< 39.8.8
>= 40.0.0-alpha.1, < 40.9.0
>= 41.0.0-alpha.1, < 41.2.1
>= 42.0.0-alpha.1, < 42.0.0-beta.3
Patched versions
39.8.8
40.9.0
41.2.1
42.0.0-beta.3
Description
Published to the GitHub Advisory Database
Aug 5, 2026
Reviewed
Aug 5, 2026
Last updated
Aug 5, 2026
Impact
Some window options supplied by web content in the
window.open()features string were applied to the newBrowserWindowwithout 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.Apps are only affected if untrusted content can call
window.open()and the app does not override child window options viasetWindowOpenHandler. Apps that denywindow.open()for untrusted content, or setoverrideBrowserWindowOptionsexplicitly, are not affected.Workarounds
Return
{ action: 'deny' }fromsetWindowOpenHandlerfor untrusted content, or supplyoverrideBrowserWindowOptionsso every window option is set explicitly.Fixed Versions
42.0.0-beta.341.2.140.9.039.8.8For more information
If you have any questions or comments about this advisory, email Electron at security@electronjs.org
References