MediumGHSA-ff2p-hmqr-hxm4CVE-2026-70610

Electron: contextBridge object copy honors prototype setters

Published 5 Aug 2026 · Updated 5 Aug 2026

Affected packages

electronnpm
Affected
<39.8.9
Fixed in
39.8.9
Update to the fixed version for your release line, for example:npm install electron@39.8.9
electronnpm
Affected
>=40.0.0-alpha.1 <40.9.2
Fixed in
40.9.2
Update to the fixed version for your release line, for example:npm install electron@40.9.2
electronnpm
Affected
>=41.0.0-alpha.1 <41.2.2
Fixed in
41.2.2
Update to the fixed version for your release line, for example:npm install electron@41.2.2
electronnpm
Affected
>=42.0.0-alpha.1 <42.0.0-beta.4
Fixed in
42.0.0-beta.4
Update to the fixed version for your release line, for example:npm install electron@42.0.0-beta.4

Details

Impact

Objects copied across the contextBridge boundary from untrusted content could carry an attacker-influenced prototype, enabling prototype-pollution-style attacks against preload code despite context isolation being enabled.

Apps are only affected if their preload code accepts object arguments from untrusted content and reads properties from them without own-property checks. Apps that only accept primitive arguments, or that validate object arguments, are not affected.

Workarounds

Validate objects received from untrusted content with own-property checks (Object.hasOwn), or copy them onto a null-prototype object before use.

Fixed Versions

  • 42.0.0-beta.4
  • 41.2.2
  • 40.9.2
  • 39.8.9

For more information

If you have any questions or comments about this advisory, email Electron at [security@electronjs.org](mailto:security@electronjs.org)

Is GHSA-ff2p-hmqr-hxm4 in any of your client repos?

Checking one package by hand is fine. Checking it across forty client projects is not. NPMscan reads the lockfiles in every GitHub repo you pick, finds each project with an affected electron, and gives you the command that fixes it.

Scan a project free, no signupOr connect GitHub to scan every repo

References

Advisory data from OSV.dev (opens OSV.dev in a new tab), refreshed daily.