CVE-2026-70608

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

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 [email protected]

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.

CVE-2026-70608 has a CVSS score of 7.2 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (42.0.1, 41.10.3, 39.8.10); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

1. What is CVE-2026-70608? CVE-2026-70608 is a high-severity security vulnerability in electron (npm), affecting versions >= 42.0.0-alpha.1, < 42.0.1. It is fixed in 42.0.1, 41.10.3, 39.8.10.
2. How severe is CVE-2026-70608? CVE-2026-70608 has a CVSS score of 7.2 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of electron are affected by CVE-2026-70608? electron (npm) versions >= 42.0.0-alpha.1, < 42.0.1 is affected.
4. Is there a fix for CVE-2026-70608? Yes. CVE-2026-70608 is fixed in 42.0.1, 41.10.3, 39.8.10. Upgrade to this version or later.
5. Is CVE-2026-70608 exploitable, and should I be worried? Whether CVE-2026-70608 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-70608 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-70608?
   • Upgrade electron to 42.0.1 or later
   • Upgrade electron to 41.10.3 or later
   • Upgrade electron to 39.8.10 or later

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