CVE-2026-34765 — electron
MEDIUMCVE-2026-34765 is a medium-severity (CVSS 6) CWE-668 vulnerability in electron. A fix is available for electron — see the affected versions and patch details below.
Electron named window.open targets not scoped to the opener's browsing context
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-34765.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
electronnpmDescription
Impact
When a renderer calls window.open() with a target name, Electron did not correctly scope the named-window lookup to the opener's browsing context group. A renderer could navigate an existing child window that was opened by a different, unrelated renderer if both used the same target name. If that existing child was created with more permissive webPreferences (via setWindowOpenHandler's overrideBrowserWindowOptions), content loaded by the second renderer inherits those permissions.
Apps are only affected if they open multiple top-level windows with differing trust levels and use setWindowOpenHandler to grant child windows elevated webPreferences such as a privileged preload script. Apps that do not elevate child window privileges, or that use a single top-level window, are not affected.
Apps that additionally grant nodeIntegration: true or sandbox: false to child windows (contrary to the security recommendations) may be exposed to arbitrary code execution.
Workarounds
Deny window.open() in renderers that load untrusted content by returning { action: 'deny' } from setWindowOpenHandler. Avoid granting child windows more permissive webPreferences than their opener.
Fixed Versions
42.0.0-alpha.541.1.040.8.539.8.5
For more information
If you have any questions or comments about this advisory, email us at [email protected]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | electron | all versions | 39.8.5npm install electron@39.8.5 |
| 📦npm | electron | ≥ 40.0.0-alpha.1&&< 40.8.5 | 40.8.5npm install electron@40.8.5 |
| 📦npm | electron | ≥ 41.0.0-alpha.1&&< 41.1.0 | 41.1.0npm install electron@41.1.0 |
| 📦npm | electron | ≥ 42.0.0-alpha.1&&< 42.0.0-alpha.5 | 42.0.0-alpha.5npm install electron@42.0.0-alpha.5 |
Affected Products
electronelectronjsDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for electron, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update electron to 39.8.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-34765 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
To mitigate this issue, Electron application developers should avoid granting elevated `webPreferences` to child windows, particularly `nodeIntegration: true` or `sandbox: false`, when using `setWindowOpenHandler`. Applications should also ensure consistent trust levels across multiple top-level windows or avoid using named windows with `window.open()` across different trust contexts.Source: Red Hat security advisory for CVE-2026-34765 (CC BY 4.0)
Frequently Asked Questions
Is CVE-2026-34765 in your dependencies?
Find it across npm, including transitive dependencies.