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Fencer Intel
medium 5.3

CVE-2026-34776 json

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

published 7mo ago modified 3mo ago also EUVD-2026-18951 , GHSA-3c8v-cfp5-9885

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 12%
public exploits
0
none known

Summary

Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to versions 38.8.6, 39.8.1, 40.8.1, and 41.0.0, 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. This issue has been patched in versions 38.8.6, 39.8.1, 40.8.1, and 41.0.0.

Patch / fix

  • npm electron 38.8.6, 39.8.1, 40.8.1, 41.0.0
  • atom electron 38.8.6, 39.8.1, 40.8.1, 41.0.0
  • electronjs electron 38.8.6, 39.8.1, 40.8.1, 41.0.0

Is CVE-2026-34776 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-34776 updated cvss 5.3

Electron: Electron: Information disclosure via crafted second-instance message

  • Red Hat Build of Podman Desktop podman-desktop-macos-1-0, podman-desktop-windows-1-0 Red Hat Build of Podman Desktop - Tech Preview rhdesktop/rh-podman-desktop-ext-openshift-local-rhel10
    affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
7mo ago

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:L
GitHub 3.1 5.3 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:L
NVD 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Affected packages

ecosystem package affected fixed in
npm electron
<38.8.6
>=39.0.0-alpha.1, <39.8.1
>=40.0.0-alpha.1, <40.8.1
>=41.0.0-alpha.1, <41.0.0
38.8.6
39.8.1
40.8.1
41.0.0

Affected products

  • electron electron

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.