CVE-2026-70599

Electron: Permission Check Handler Receives Main Frame Origin Instead of Requesting Iframe Origin

Workarounds

Check details.securityOrigin instead of requestingOrigin for these permissions, or do not delegate device permissions to untrusted iframes.

Fixed Versions

• 42.0.0-beta.1
• 41.2.0
• 40.9.0
• 39.8.7

For more information

If you have any questions or comments about this advisory, email Electron at [email protected]

For serial-port and media (camera / microphone) permission checks made from an iframe, the requestingOrigin passed to session.setPermissionCheckHandler was the top-level frame's origin rather than the requesting frame's. Origin-based handler logic could therefore grant a cross-origin iframe device access intended only for the top-level origin.

Apps are only affected if they use setPermissionCheckHandler with origin-based logic and embed cross-origin iframes with delegated device permissions. Apps that base the decision on details.securityOrigin, or that do not embed such iframes, are not affected.

CVE-2026-70599 has a CVSS score of 5.9 (Medium). 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 (39.8.7, 40.9.0, 41.2.0, 42.0.0-beta.1); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

1. What is CVE-2026-70599? CVE-2026-70599 is a medium-severity security vulnerability in electron (npm), affecting versions < 39.8.7. It is fixed in 39.8.7, 40.9.0, 41.2.0, 42.0.0-beta.1.
2. How severe is CVE-2026-70599? CVE-2026-70599 has a CVSS score of 5.9 (Medium). 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-2026-70599? electron (npm) versions < 39.8.7 is affected.
4. Is there a fix for CVE-2026-70599? Yes. CVE-2026-70599 is fixed in 39.8.7, 40.9.0, 41.2.0, 42.0.0-beta.1. Upgrade to this version or later.
5. Is CVE-2026-70599 exploitable, and should I be worried? Whether CVE-2026-70599 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-2026-70599 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-2026-70599?
   • Upgrade electron to 39.8.7 or later
   • Upgrade electron to 40.9.0 or later
   • Upgrade electron to 41.2.0 or later
   • Upgrade electron to 42.0.0-beta.1 or later

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