What is CVE-2026-34778?

CVE-2026-34778 is a medium-severity vulnerability in Electron, classified under Authentication Bypass by Spoofing. CVSS score: 5.9/10. Published 2026-04-04.

How severe is CVE-2026-34778?

Medium severity. CVSS v3 base score is 5.9 out of 10.

Vulnerability in Electron

CVE-2026-34778

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.

EPSS: 0.001 (2.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N.

Affected products

Electron — versions < 38.8.6, >= 39.0.0-alpha.1, < 39.8.1, >= 40.0.0-alpha.1, < 40.8.1
Electronjs Electron — versions 41.0.0

Weakness classification (CWE)

References

security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)

Frequently asked questions

What is CVE-2026-34778?: CVE-2026-34778 is a medium-severity vulnerability in Electron, classified under Authentication Bypass by Spoofing. CVSS score: 5.9/10. Published 2026-04-04.
How severe is CVE-2026-34778?: Medium severity. CVSS v3 base score is 5.9 out of 10.