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

CVE-2026-34776 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

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]

Basic information

Type
reviewed
Severity
medium
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2026-04-03 02:43:59 UTC
Updated
2026-04-06 23:11:06 UTC
GitHub reviewed
2026-04-03 02:43:59 UTC
NVD published
2026-04-04 00:16:18 UTC

EPSS Score

Score Percentile
0.01% 2.92%

CVSS Scores

Base score Version Severity Vector
5.3 3.1 —
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:L Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.

Identifiers

Type Value
GHSA GHSA-3c8v-cfp5-9885 ↗
CVE CVE-2026-34776 ↗

CWEs

CWE id Name
CWE-125 Out-of-bounds Read

Affected packages (4)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
npm electron < 38.8.6 38.8.6 —
npm electron >= 39.0.0-alpha.1, < 39.8.1 39.8.1 —
npm electron >= 40.0.0-alpha.1, < 40.8.1 40.8.1 —
npm electron >= 41.0.0-alpha.1, < 41.0.0 41.0.0 —

References

cvelogic Threat Intelligence