GHSA-xj5x-m3f3-5x3h CVE-2026-34778

Electron: Service worker can spoof executeJavaScript IPC replies

Medium npm

Severity: 5.9 / 10; Medium · CVSS 3.1
Exploit chance (EPSS): 0.13%; Chance of exploitation in the next 30 days. Higher than 2.51% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-290 Authentication Bypass by Spoofing; CWE-345 Insufficient Verification of Data Authenticity
Fix: 38.8.6; Upgrade electron to this version or later

Description

Impact

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.

Workarounds

Do not trust the return value of webContents.executeJavaScript() for security decisions. Use dedicated, validated IPC channels for security-relevant communication with renderers.

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

Affected versions

npm

Package	Vulnerable	Fixed in
electron	`< 38.8.6`	`38.8.6`
electron	`>= 39.0.0-alpha.1, < 39.8.1`	`39.8.1`
electron	`>= 40.0.0-alpha.1, < 40.8.1`	`40.8.1`
electron	`>= 41.0.0-alpha.1, < 41.0.0`	`41.0.0`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

electron npm → `38.8.6`

npm

npm install electron@38.8.6

yarn

yarn add electron@38.8.6

pnpm

pnpm add electron@38.8.6

Severity breakdown

CVSS 3.1 5.9

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N

Attack vector: Network
Attack complexity: High
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: High
Availability: None

Weakness

CWE-290: Authentication Bypass by Spoofing

This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.

CWE-345: Insufficient Verification of Data Authenticity

The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.

References

Advisories

nvd.nist.gov/vuln/detail/CVE-2026-34778

Packages

github.com/electron/electron

Timeline

Apr 3, 2026 Published
Jul 24, 2026 Last updated by the source
Oct 31, 2026 Latest EPSS score

Advisory	Severity	Why it's related
GHSA-qqvq-6xgj-jw8g Electron affected by libvpx's heap buffer overflow in vp8 encoding	High Known exploited	Also affects electron
GHSA-j7hp-h8jx-5ppr libwebp: OOB write in BuildHuffmanTable	High Known exploited	Also affects electron
GHSA-995f-9x5r-2rcj Heap buffer overflow in GPU	Critical Known exploited	Also affects electron
GHSA-jr5w-w6x2-84p9 Electron: Mitigation for compromised eMudhra intermediate certificates	High	Also affects electron
GHSA-h3v5-h239-pg29 Electron: Off-screen rendering on macOS trusts GPU-supplied frame geometry	Low	Also affects electron
GHSA-3qxv-5xgr-q7w9 Electron: Frame subscription trusts GPU-supplied frame geometry	Low	Also affects electron
GHSA-997q-gvvc-jwmx Electron: openExternal permission requests can be attributed to the wrong origin	Medium	Also affects electron
GHSA-fw47-9c62-h3vw Electron: HID and USB permission checks can be attributed to the wrong origin	Medium	Also affects electron

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