CVE-2026-70602 in Electron
Summary
by MITRE • 08/05/2026
Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 39.8.8, 40.9.0, 41.2.1, and 42.0.0-beta.3, 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. This issue is fixed in versions 39.8.8, 40.9.0, 41.2.1, and 42.0.0-beta.3.
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Analysis
by VulDB Data Team • 08/05/2026
This vulnerability affects the Electron framework, which enables developers to build cross-platform desktop applications using web technologies including JavaScript, HTML, and CSS. The security flaw specifically relates to how extension tab and scripting APIs handle session scoping, creating a critical privilege escalation risk that undermines application isolation mechanisms. Prior to versions 39.8.8, 40.9.0, 41.2.1, and 42.0.0-beta.3, the framework failed to properly isolate extension sessions, allowing malicious or compromised extensions to access resources belonging to different user sessions. This represents a fundamental breakdown in the security model that Electron employs to separate application contexts and maintain user data integrity across multiple extension instances.
The technical implementation flaw stems from insufficient session boundary enforcement within Electron's extension management system. When applications utilize session.loadExtension to load Chrome extensions, the framework should maintain strict separation between different extension sessions to prevent cross-session interference. However, the vulnerability allowed a compromised extension in one session to execute navigation commands, perform scripting operations, and access read operations on windows belonging to other sessions. This breach of isolation occurs at the API level where tab and scripting functionality lacks proper scope validation against session boundaries. The issue aligns with CWE-276, which addresses improper privilege management and inadequate access control mechanisms in software systems.
The operational impact of this vulnerability is severe for applications that rely on session-based isolation as a security control mechanism. Attackers could potentially exploit this weakness to gain unauthorized access to sensitive user data, perform cross-session surveillance, or execute malicious actions across multiple application contexts. This threat becomes particularly dangerous when applications load extensions dynamically and depend on session separation to protect against extension-based attacks. The vulnerability essentially allows an attacker with access to one extension session to impersonate or manipulate other sessions, creating a vector for persistent threats that could compromise user privacy and application integrity.
Applications are specifically at risk when they implement dynamic extension loading using session.loadExtension and assume that separate sessions provide adequate isolation from malicious extensions. This vulnerability undermines the security assumptions made by developers who rely on Electron's session management capabilities to maintain separation between different application contexts. The fix implemented in versions 39.8.8, 40.9.0, 41.2.1, and 42.0.0-beta.3 addresses the core issue by enforcing proper session scoping for extension APIs, ensuring that tab and scripting operations are confined to their originating extension session. Organizations should prioritize updating their Electron-based applications to these patched versions while implementing additional monitoring for suspicious extension behavior and reviewing extension loading practices within their applications. This vulnerability also maps to ATT&CK technique T1106, which covers the execution of malicious code through legitimate system processes, as compromised extensions could leverage this weakness to extend their reach beyond intended boundaries.
The remediation approach requires immediate application updates to the patched Electron versions while maintaining security awareness regarding extension loading practices. Development teams should implement comprehensive testing procedures to validate session isolation mechanisms and consider additional security controls such as extension signature verification and runtime monitoring for unauthorized cross-session activities. This vulnerability highlights the importance of proper API scoping and session management in framework-level security implementations, particularly when dealing with privileged operations that could enable lateral movement within application environments.