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.