What’s Vulnerable › Vulnerabilities
CVE-2026-70604: Electron: Custom protocol with supportFetchAPI but not corsEnabled allows cross-origin reads
- Severity: high (CVSS 7.4 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-08-05 · updated 2026-10-08
- Weakness: CWE-942
Description
Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 39.8.10, 40.9.3, 41.4.0, and 42.0.0, a custom scheme registered with supportFetchAPI: true but without corsEnabled: true was not subject to CORS enforcement. A page loaded from a remote origin could therefore fetch() or XMLHttpRequest that scheme cross-origin and read the full response body, rather than the read being blocked. Apps that serve sensitive data from such a scheme and load remote or untrusted content in a renderer are affected. This issue is fixed in versions 39.8.10, 40.9.3, 41.4.0, and 42.0.0.
Affected products
- electron: before 39.8.10; from 40.0.0 before 40.9.3; from 41.0.0 before 41.4.0; 42.0.0-alpha1, 42.0.0-alpha2, 42.0.0-alpha3, 42.0.0-alpha4, 42.0.0-alpha5, 42.0.0-alpha6 (+8) — fixed in 39.8.10, 40.9.3, 41.4.0
How to fix
Upgrade to a fixed version: electron 39.8.10, 40.9.3, 41.4.0. Check the vendor advisory for mitigations.
References
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