Electron: window.open features string controls some window options considered privileged

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS

• CVE-2026-70607: 0.56% estimated exploitation activity in the next 30 days; percentile 46.54 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact Some window options supplied by web content in the window.open() features string were applied to the new BrowserWindow without 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 via setWindowOpenHandler. Apps that deny window.open() for untrusted content, or set overrideBrowserWindowOptions explicitly, are not affected. Workarounds Return { action: 'deny' } from setWindowOpenHandler for untrusted content, or supply overrideBrowserWindowOptions so every window option is set explicitly. Fixed Versions 42.0.0-beta.3 41.2.1 40.9.0 39.8.8 For more information If you have any questions or comments about this advisory, email Electron at security@electronjs.org

Published by the source

5 Aug 2026, 16:24 UTC

Last modified by the source

5 Aug 2026, 16:24 UTC

Source last checked

26 Oct 2026, 13:00 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-v93f-fgjr-hjrj

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# Patch Next advisory brief: CVE-2026-70607

Advisory: Electron: window.open features string controls some window options considered privileged
IDs: CVE-2026-70607, GHSA-v93f-fgjr-hjrj
Record: https://patchnext.com/advisories/cve-2026-70607 (revision 1, source checked 26 Oct 2026, 13:00 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: electron 42.0.0-beta.3, 41.2.1, 40.9.0, 39.8.8. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm electron: affected < 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; fixed in 42.0.0-beta.3, 41.2.1, 39.8.8, 40.9.0

## Suggested inspection (read-only)
- `npm ls electron --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on electron.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-v93f-fgjr-hjrj (GitHub-reviewed advisory GHSA-v93f-fgjr-hjrj lists affected ranges: npm electron >=0 =40.0.0-alpha.1 =41.0.0-alpha.1 =42.0.0-alpha.1 <42.0.0-beta.3)

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