CVE-2026-34778

CVE-2026-34778 is a medium-severity vulnerability in Electronjs Electron with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-290.

Key facts

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2026-34778?
CVE-2026-34778 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability none.
Is CVE-2026-34778 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-34778?
CVE-2026-34778 primarily affects Electronjs Electron. In total, 15 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-34778?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-34778 have an EU (EUVD) identifier?
Yes. CVE-2026-34778 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18955.
When was CVE-2026-34778 published?
CVE-2026-34778 was published on 2026-04-04 and last updated on 2026-06-17.

References

Affected products (15)

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