# CVE-2026-34767: Electron: HTTP Response Header Injection in custom protocol handlers and webRequest

> Attackers can inject HTTP response headers in Electron apps using custom protocols or webRequest, potentially bypassing security controls like CSP or cookies.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 3 Apr 2026
- **Updated:** 6 Apr 2026
- **Also known as:** GHSA-4p4r-m79c-wq3v

## What is CVE-2026-34767?

CVE-2026-34767 is a medium-severity vulnerability in Electronjs Electron, published on 3 Apr 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to versions 38.8.6, 39.8.3, 40.8.3, and 41.0.3, 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. This issue has been patched in versions 38.8.6, 39.8.3, 40.8.3, and 41.0.3.

Weakness: CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component), CWE-113 (Improper Neutralization of CRLF Sequences in HTTP Headers)

## Which versions are affected by CVE-2026-34767?

8 open source packages ship an affected version, including electron. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `electron` | npm | All versions | 38.8.6 |
| `electron` | npm | All versions | 38.8.6 |
| `electron` | npm | From 39.0.0-alpha.1 | 39.8.3 |
| `electron` | npm | From 39.0.0-alpha.1 | 39.8.3 |
| `electron` | npm | From 40.0.0-alpha.1 | 40.8.3 |
| `electron` | npm | From 40.0.0-alpha.1 | 40.8.3 |
| `electron` | npm | From 41.0.0-alpha.1 | 41.0.3 |
| `electron` | npm | From 41.0.0-alpha.1 | 41.0.3 |

Products: Electronjs Electron.

## How do I fix CVE-2026-34767?

Upgrade electron to a fixed version for your release line: 38.8.6, 39.8.3, 40.8.3 or 41.0.3.

## Is CVE-2026-34767 being exploited?

There is no known exploitation of CVE-2026-34767 in the wild and no public exploit code.

## Other vulnerabilities in Electronjs Electron

- [CVE-2017-16151](https://insights.sbomify.com/CVE-2017-16151/): Chromium Remote Code Execution in electron (critical 9.8)
- [CVE-2018-1000118](https://insights.sbomify.com/CVE-2018-1000118/): Electron protocol handler browser vulnerable to Command Injection (high 8.8)
- [CVE-2026-34780](https://insights.sbomify.com/CVE-2026-34780/): Electron: Context Isolation bypass via contextBridge VideoFrame transfer (high 8.4)
- [CVE-2026-102676](https://insights.sbomify.com/CVE-2026-102676/): Electron: <webview> can enable Node.js integration in Web Workers despite embedder restrictions (high 8.3)
- [CVE-2026-102673](https://insights.sbomify.com/CVE-2026-102673/): Electron drops inherited HTML sandbox restrictions for popups opened through OpenURLFromTab (high 8.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-34767 and fix it if it is affected.

What it is: CVE-2026-34767 is a medium-severity vulnerability in Electronjs Electron, published on 3 Apr 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-34767 in the wild and no public exploit code.

Affected packages and fixed versions:
- electron (npm): affected all versions; fixed in 38.8.6
- electron (npm): affected all versions; fixed in 38.8.6
- electron (npm): affected from 39.0.0-alpha.1; fixed in 39.8.3
- electron (npm): affected from 39.0.0-alpha.1; fixed in 39.8.3
- electron (npm): affected from 40.0.0-alpha.1; fixed in 40.8.3
- electron (npm): affected from 40.0.0-alpha.1; fixed in 40.8.3
- electron (npm): affected from 41.0.0-alpha.1; fixed in 41.0.3
- electron (npm): affected from 41.0.0-alpha.1; fixed in 41.0.3

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-34767/ (Markdown: https://insights.sbomify.com/CVE-2026-34767/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34767
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34767
- OSV: https://osv.dev/vulnerability/CVE-2026-34767

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-34767/
Summaries are generated and may contain mistakes; the official description above is the record.