Electron up to 39.8.9/40.9.2/41.3.9 Custom Scheme cross-domain policy

Summaryinfo

A vulnerability classified as problematic has been found in Electron up to 39.8.9/40.9.2/41.3.9. This affects an unknown function of the component Custom Scheme. The manipulation leads to cross-domain policy. This vulnerability is listed as CVE-2026-70604. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Electron up to 39.8.9/40.9.2/41.3.9. This issue affects some unknown processing of the component Custom Scheme. The manipulation with an unknown input leads to a cross-domain policy vulnerability. Using CWE to declare the problem leads to CWE-942. The product uses a cross-domain policy file that includes domains that should not be trusted. Impacted is confidentiality. The summary by CVE is:

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.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-70604 since 08/04/2026. The exploitation is known to be difficult. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available.

Upgrading to version 39.8.10, 40.9.3, 41.4.0 or 42.0.0 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

• Electron

Version

• 39.8.0
• 39.8.1
• 39.8.2
• 39.8.3
• 39.8.4
• 39.8.5
• 39.8.6
• 39.8.7
• 39.8.8
• 39.8.9
• 40.9.0
• 40.9.1
• 40.9.2
• 41.3.0
• 41.3.1
• 41.3.2
• 41.3.3
• 41.3.4
• 41.3.5
• 41.3.6
• 41.3.7
• 41.3.8
• 41.3.9

Website

• Product: https://github.com/electron/electron/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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