dbcve.org
ElectronApplication · Electronjs

CVE-2026-34774

HIGH · 8.1 CVSS v3.1 Published 2026-04-04
Fix available
A fix is available. Upgrade to 39.8.1 / 40.7.0 or later.
See remediation →
90/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Use-after-free vulnerability in Electron where destroying a parent offscreen WebContents while a child window remains open causes the child to dereference freed memory during paint frames, leading to potential crash or memory corruption. Only affects apps using both offscreen rendering (webPreferences.offscreen: true) and permitting child windows via setWindowOpenHandler.

MitigationUpdate Electron to version 39.8.1, 40.7.0, or 41.0.0 or later; alternatively, disable offscreen rendering or prevent child windows if immediate update is not feasible.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
ElectronApplication
Affected:< 39.8.1>= 40.0.0, < 40.7.0= 41.0.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Electron version
    Run 'npm list electron' or check the electron version in your package.json, or run 'electron --version' in the application context
    Affected if version is < 39.8.1, or >= 40.0.0 and < 40.7.0, or exactly 41.0.0
  2. Verify offscreen rendering is enabled
    Search your codebase for webPreferences configuration objects containing 'offscreen: true' in BrowserWindow or webContents creation
    Affected if offscreen rendering is enabled in any webPreferences configuration
  3. Check for child window permission handler
    Search your codebase for setWindowOpenHandler implementation that returns an action allowing window creation (such as { action: 'allow' })
    Affected if setWindowOpenHandler is used and permits child windows to open

Environment is affected only if all three conditions are true: the Electron version falls within the affected ranges, offscreen rendering is enabled, and child windows are permitted via setWindowOpenHandler.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 39.8.1 / 40.7.0 or later
Fixed in 39.8.140.7.0
Interim mitigation

Update Electron to version 39.8.1, 40.7.0, or 41.0.0 or later; alternatively, disable offscreen rendering or prevent child windows if immediate update is not feasible.

Recommended fix High confidence

Upgrade to Electron 39.8.1, 40.7.0, or 41.0.0 depending on your current major version branch

  1. 1. Identify the current Electron version in your project by checking package.json or running 'npm list electron'
  2. 2. Determine which major version branch you are on (39.x, 40.x, or 41.x) to select the appropriate upgrade target
  3. 3. Update the Electron version in package.json to the fixed version for your branch: 39.8.1 for 39.x, 40.7.0 for 40.x, or 41.0.0 for 41.x
  4. 4. Run 'npm install' or 'npm update' to fetch the new Electron version
  5. 5. Rebuild any native modules compatible with Electron using 'electron-rebuild' or similar tooling
  6. 6. Test your application thoroughly, especially any offscreen rendering functionality and child window behavior
  7. 7. Verify the fix by confirming the Electron version matches the target (e.g., run 'npx electron --version')
Caveat Electron upgrades may include Chromium updates that affect rendering or APIs; review release notes for your target version for any breaking changes

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Electron Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing6.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,020
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,232.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-34774 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-34774 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data