CVE-2026-34767

Electron: HTTP Response Header Injection in custom protocol handlers and webRequest

Impact

Apps that register custom protocol handlers via protocol.handle() / protocol.registerSchemesAsPrivileged() or modify response headers via webRequest.onHeadersReceived may be vulnerable to HTTP response header injection if attacker-controlled input is reflected into a response header name or value.

An attacker who can influence a header value may be able to inject additional response headers, affecting cookies, content security policy, or cross-origin access controls.

Apps that do not reflect external input into response headers are not affected.

Workarounds

Validate or sanitize any untrusted input before including it in a response header name or value.

Fixed Versions

• 41.0.3
• 40.8.3
• 39.8.3
• 38.8.6

For more information

If there are any questions or comments about this advisory, send an email to security@electronjs.org