Improper input validation in Electron
CVE-2026-34773
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 Windows, app.setAsDefaultProtocolClient(protocol) did not validate the protocol name before writing to the registry. Apps that pass untrusted input as the protocol name may allow an attacker to write to arbitrary subkeys under HKCU\Software\Classes\, potentially hijacking existing protocol handlers. Apps are only affected if they call app.setAsDefaultProtocolClient() with a protocol name derived from external or untrusted input. Apps that use a hardcoded protocol name are not affected. This issue has been patched in versions 38.8.6, 39.8.1, 40.8.1, and 41.0.0.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.003 (17.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 17th percentile — 17.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.000
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
- github.com/electron/electron/security/advisories/GHSA-mwmh-mq4g-g6gr (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-34773?
- CVE-2026-34773 is a medium-severity vulnerability in Electron, classified under Improper Input Validation. CVSS score: 4.7/10. Published 2026-04-04.
- How severe is CVE-2026-34773?
- Medium severity. CVSS v3 base score is 4.7 out of 10.