Electron: Windows opened from a sandboxed top-level document do not inherit its sandbox restrictions

### Impact Windows opened from a sandboxed top-level document did not inherit that document's HTML `sandbox` restrictions, so content that was meant to run sandboxed could open a window with the app's full origin. GHSA-hq2x-r82h-9wj4 covers the same issue for sandboxed iframes. Apps are only affected if they render untrusted content in a sandboxed top-level document that allows popups. Apps that deny popups from untrusted content with `setWindowOpenHandler` are not affected. ### Workarounds Return `{ action: 'deny' }` from `setWindowOpenHandler` for windows opened by untrusted content. ### Fixed Versions * `44.0.0-beta.5` * `43.4.1` * `42.9.2` * `41.10.6` ### For more information If you have any questions or comments about this advisory, email us at [[email protected]](mailto:[email protected])

Source published

29 Sep 2026 18:05:11 UTC

Source modified

29 Sep 2026 18:15:04 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N

Publisher rating · HIGH