# CVE-2026-70602: Electron session isolation bypass in extension tab and scripting APIs

Source: https://junglewise.ai/threats/cve-2026-70602-electron-session-isolation-bypass-in-extension-tab-and-scripting  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-05. Updated: 2026-08-05  
License: CC BY 4.0 with a link back

CVE-2026-70602 · Severity: medium · CVSS 6.6 · Published 2026-08-05

Electron, a framework used to build desktop applications, contains a security flaw where browser extensions can bypass intended isolation boundaries. A malicious or compromised extension could potentially view or interact with data in other parts of the application that it should not have access to. This risk only applies to applications that load Chrome extensions and attempt to isolate them using separate sessions.

Technologies: [electron (npm)](https://junglewise.ai/threats/technologies/electron). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-70602 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-70602 being exploited in the wild.

**How severe is CVE-2026-70602?** Medium severity, with a CVSS score of 6.6, published 5 August 2026.

**Which products and versions are affected?** electron (npm) SEMVER:introduced=0,fixed=39.8.8.

**Is there a fix for CVE-2026-70602?** Yes. electron (npm): upgrade to 39.8.8 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-70602 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-70602?** Check whether you run electron (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- electron (npm): upgrade to 39.8.8 or later

  ```sh
  npm install electron@39.8.8
  ```


## Technical details

A vulnerability in Electron's extension handling allows extension tab and scripting APIs to operate across session boundaries. The root cause is that these APIs were not properly scoped to the extension's own 'session' object. An attacker who successfully loads a malicious extension via 'session.loadExtension' can navigate, script, and read data from windows belonging to entirely different sessions within the same application. This bypasses the security isolation typically provided by Electron sessions. The issue is fixed in versions 39.8.8, 40.9.0, 41.2.1, and 42.0.0-beta.3.

## Affected products

- Electron electron < 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

## Identifiers

- CVE-2026-70602
- GHSA-m55f-7gqj-fr98

## Timeline

- 2026-07-27: disclosed
- 2026-08-05: advisory

## References

- [https://github.com/electron/electron/security/advisories/GHSA-m55f-7gqj-fr98](https://github.com/electron/electron/security/advisories/GHSA-m55f-7gqj-fr98)
- [https://api.github.com/repos/electron/electron/security-advisories/GHSA-m55f-7gqj-fr98](https://api.github.com/repos/electron/electron/security-advisories/GHSA-m55f-7gqj-fr98)

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