CVE-2026-34776: Electron: Out-of-bounds read in second-instance IPC on macOS and Linux

April 3, 2026 (updated April 6, 2026)

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.

References

github.com/advisories/GHSA-3c8v-cfp5-9885
github.com/electron/electron
github.com/electron/electron/security/advisories/GHSA-3c8v-cfp5-9885
nvd.nist.gov/vuln/detail/CVE-2026-34776

Code Behaviors & Features

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