CVE-2026-34776

MEDIUM5.3EPSS 0.01%

Electron: Out-of-bounds read in second-instance IPC on macOS and Linux

Published: 4/3/2026Modified: 4/6/2026

Description

### Impact On macOS and Linux, apps that call `app.requestSingleInstanceLock()` were vulnerable to an out-of-bounds heap read when parsing a crafted second-instance message. Leaked memory could be delivered to the app's `second-instance` event handler. This issue is limited to processes running as the same user as the Electron app. Apps that do not call `app.requestSingleInstanceLock()` are not affected. Windows is not affected by this issue. ### Workarounds There are no app side workarounds, developers must update to a patched version of Electron. ### Fixed Versions * `41.0.0` * `40.8.1` * `39.8.1` * `38.8.6` ### For more information If there are any questions or comments about this advisory, please email [[email protected]](mailto:[email protected])

Affected packages (1)

CVSS scores

SourceVersionSeverityVector
osvCVSS 3.1MEDIUM5.3CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:L

References (3)