CVE-2026-34767
Electron: HTTP Response Header Injection in custom protocol handlers and webRequest
Description
### 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](mailto:security@electronjs.org)
How to fix CVE-2026-34767
To remediate CVE-2026-34767, upgrade the affected package to a fixed version below.
- —upgrade to 38.8.6 or later
Is CVE-2026-34767 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 38.8.6
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:N |