# CVE-2026-34774: Electron: Use-after-free in offscreen child window paint callback

> Electron apps using offscreen rendering and child windows are vulnerable to use-after-free, potentially allowing code execution or crashes.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 3 Apr 2026
- **Updated:** 15 Jul 2026
- **Also known as:** GHSA-532v-xpq5-8h95

## What is CVE-2026-34774?

CVE-2026-34774 is a high-severity use after free vulnerability in Electronjs Electron, published on 3 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to versions 39.8.1, 40.7.0, and 41.0.0, apps that use offscreen rendering and allow child windows via window.open() may be vulnerable to a use-after-free. If the parent offscreen WebContents is destroyed while a child window remains open, subsequent paint frames on the child dereference freed memory, which may lead to a crash or memory corruption. Apps are only affected if they use offscreen rendering (webPreferences.offscreen: true) and their setWindowOpenHandler permits child windows. Apps that do not use offscreen rendering, or that deny child windows, are not affected. This issue has been patched in versions 39.8.1, 40.7.0, and 41.0.0.

Weakness: CWE-825 (Expired Pointer Dereference), CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-34774?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `electron` | npm | All versions | 39.8.1 |
| `electron` | npm | All versions | 39.8.1 |
| `electron` | npm | From 40.0.0-alpha.1 | 40.7.0 |
| `electron` | npm | From 40.0.0-alpha.1 | 40.7.0 |
| `electron` | npm | From 41.0.0-alpha.1 | 41.0.0 |
| `electron` | npm | From 41.0.0-alpha.1 | 41.0.0 |

Products: Electronjs Electron.

## How do I fix CVE-2026-34774?

Upgrade electron to a fixed version for your release line: 39.8.1, 40.7.0 or 41.0.0.

## Is CVE-2026-34774 being exploited?

There is no known exploitation of CVE-2026-34774 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-2026-34774 and fix it if it is affected.

What it is: CVE-2026-34774 is a high-severity use after free vulnerability in Electronjs Electron, published on 3 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-34774 in the wild and no public exploit code.

Affected packages and fixed versions:
- electron (npm): affected all versions; fixed in 39.8.1
- electron (npm): affected all versions; fixed in 39.8.1
- electron (npm): affected from 40.0.0-alpha.1; fixed in 40.7.0
- electron (npm): affected from 40.0.0-alpha.1; fixed in 40.7.0
- electron (npm): affected from 41.0.0-alpha.1; fixed in 41.0.0
- electron (npm): affected from 41.0.0-alpha.1; fixed in 41.0.0

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-2026-34774/ (Markdown: https://insights.sbomify.com/CVE-2026-34774/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34774
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34774
- OSV: https://osv.dev/vulnerability/CVE-2026-34774

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-34774/
Summaries are generated and may contain mistakes; the official description above is the record.