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Fencer Vulns
medium 5.9

CVE-2026-34778 json

Electron: Service worker can spoof executeJavaScript IPC replies

published 2026-04-03 7 mo ago modified 2026-07-24 3 mo ago also EUVD-2026-18955 , GHSA-xj5x-m3f3-5x3h

cvss
5.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 2%
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, a service worker running in a session could spoof reply messages on the internal IPC channel used by webContents.executeJavaScript() and related methods, causing the main-process promise to resolve with attacker-controlled data. Apps are only affected if they have service workers registered and use the result of webContents.executeJavaScript() (or webFrameMain.executeJavaScript()) in security-sensitive decisions. 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

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-2026-34778 updated cvss 5.9

Electron: Electron: Integrity issue due to IPC channel spoofing by a service worker

  • 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
7 mo ago

Exploit prediction

0.13% chance of exploitation in the next 30 days, higher than 2% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N
GitHub 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/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
  • CWE-290 Authentication Bypass by Spoofing
  • CWE-345 Insufficient Verification of Data Authenticity

References

Sources

Fencer Vulns 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.