CVE-2026-70601

Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 39.8.9, 40.9.2, 41.2.2, and 42.0.0-beta.5, apps that expose Promise-returning functions to web content via contextBridge may be vulnerable to a context isolation bypass. Untrusted web content could obtain access to the isolated preload world and, through it, every capability the preload script has. In renderers without a sandbox, or with nodeIntegration enabled, this may escalate to Node.js access. Apps are affected if they expose Promise-returning functions via contextBridge, the standard pattern for wrapping ipcRenderer.invoke, in windows that load untrusted content. This issue is fixed in versions 39.8.9, 40.9.2, 41.2.2, and 42.0.0-beta.5.

Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 39.8.9, 40.9.2, 41.2.2, and 42.0.0-beta.5, apps that expose Promise-returning functions to web content via contextBridge may be vulnerable to a context isolation bypass. Untrusted web content could obtain access to the isolated preload world and, through it, every capability the preload script has. In renderers without a sandbox, or with nodeIntegration enabled, this may escalate to Node.js access. Apps are affected if they expose Promise-returning functions via contextBridge, the standard pattern for wrapping ipcRenderer.invoke, in windows that load untrusted content. This issue is fixed in versions 39.8.9, 40.9.2, 41.2.2, and 42.0.0-beta.5.

### Impact Apps that expose Promise-returning functions to web content via `contextBridge` may be vulnerable to a context isolation bypass. Untrusted web content could obtain access to the isolated preload world and, through it, every capability the preload script has. In renderers without a sandbox, or with `nodeIntegration` enabled, this may escalate to Node.js access. Apps are affected if they expose Promise-returning functions via `contextBridge` — the standard pattern for wrapping `ipcRenderer.invoke` — in windows that load untrusted content. Apps that never load untrusted content in those windows are not affected. ### Workarounds There are no app side workarounds, you must update to a patched version of Electron. ### Fixed Versions * `42.0.0-beta.5` * `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 [[email protected]](mailto:[email protected])