CVE-2026-102677 in Electron
Summary
by MITRE • 09/29/2026
Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. From 42.3.3 until 42.10.0, 43.5.0, and 44.0.0-beta.6, Electron's sandboxed preload code cache did not verify that a cached entry matched the preload it was served for. A compromised renderer could write attacker-controlled cache data and cause Electron to reuse it for a later load, executing the renderer's code in the more privileged preload context. The issue affects applications that load untrusted content. This issue is fixed in versions 42.10.0, 43.5.0, and 44.0.0-beta.6.
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Analysis
by VulDB Data Team • 09/30/2026
The Electron framework serves as a foundational technology for developing cross-platform desktop applications by leveraging web technologies such as JavaScript, HTML, and CSS to create native-like user interfaces. A critical security architecture within Electron involves the separation of processes into renderer processes, which handle untrusted or potentially malicious content from websites, and preload scripts that run in a more privileged context with access to Node.js APIs and system-level resources. This isolation is crucial for preventing compromised web pages from directly accessing sensitive application data or executing arbitrary code on the host machine. The vulnerability identified affects specific versions of Electron ranging from 42.3.3 through 42.10.0, as well as version 43.5.0 and beta release 44.0.0-beta.6, where a flaw in the sandboxed preload code cache mechanism undermines this security boundary.
The technical root cause of this vulnerability lies in the failure to verify that cached preload script entries correspond correctly to their intended target contexts. When Electron loads an application or web content, it may utilize a cache to store compiled preload scripts for performance optimization. However, due to insufficient validation logic within the caching subsystem, there was no mechanism ensuring that a retrieved cache entry matched the specific preload module it was being served for during execution. This lack of integrity checking creates a scenario where the mapping between cached data and its intended context is not enforced strictly enough to prevent manipulation by lower-privilege processes.
An attacker who has achieved code execution within a renderer process, typically through exploiting other vulnerabilities such as cross-site scripting or remote code execution flaws in web content loaded by the application, can exploit this flaw to write arbitrary cache data. By injecting malicious payloads into the preload script cache, the compromised renderer ensures that when Electron subsequently loads an affected page or component, it retrieves and executes the attacker-controlled cached code instead of the legitimate preload script. Because preload scripts operate with elevated privileges compared to standard web content, executing attacker-supplied code in this context effectively grants the renderer process access to Node.js APIs and system resources that should remain inaccessible, thereby escalating privileges from a sandboxed environment to one capable of full application control.
The operational impact of this vulnerability is severe for applications that load untrusted or third-party content within their Electron windows. If an attacker can trick a user into visiting a malicious website hosted in the Electron app, they can leverage this cache poisoning technique to bypass security sandboxes and execute arbitrary code with the permissions of the application itself. This could lead to data exfiltration, installation of malware, modification of local files, or complete compromise of the host system depending on the privileges under which the Electron application is running. The risk is particularly acute for applications that integrate web views containing dynamic content from external sources without rigorous input validation and isolation strategies.
This vulnerability aligns with CWE-20 Improper Input Validation, as the framework failed to adequately validate the integrity of cached data against its expected context before execution. It also relates to CWE-94 Improper Control of Generation of Code (Code Injection), since attacker-controlled code was executed in a privileged environment due to flawed logic in handling preloaded scripts. From an ATT&CK perspective, this flaw facilitates lateral movement and privilege escalation within the application's process space, allowing attackers to transition from web-based exploitation vectors to native system compromise by abusing the trust relationship between renderer processes and preload contexts.
Mitigation for this issue requires immediate upgrading of Electron dependencies to patched versions 42.10.0, 43.5.0, or later beta releases such as 44.0.0-beta.6 where the cache verification logic has been corrected. Application developers should also implement additional defensive measures including strict Content Security Policies to limit script execution sources and avoid loading untrusted content in windows that utilize privileged preload scripts whenever possible. Regular security audits of dependency chains and continuous monitoring for new Electron releases are essential practices to maintain robust application security postures against evolving threat landscapes targeting desktop frameworks.