CVE-2026-34776
Electron: Out-of-bounds read in second-instance IPC on macOS and Linux
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 [security@electronjs.org](mailto:security@electronjs.org)
How to fix CVE-2026-34776
To remediate CVE-2026-34776, upgrade the affected package to a fixed version below.
- —upgrade to 38.8.6 or later
Is CVE-2026-34776 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 38.8.6
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.3 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:L |