Extension tab and scripting APIs were not scoped to the extension's own session. A malicious or compromised extension loaded into one session could navigate, script, and read from windows belonging to a different session.

Apps are only affected if they load Chrome extensions via session.loadExtension and rely on separate sessions to isolate that extension from other content. Apps that do not load extensions, or that use a single session, are not affected.

Only load extensions from sources you trust; do not rely on session separation alone to contain an extension.

If you have any questions or comments about this advisory, email Electron at security@electronjs.org