CVE-2026-34773
highpriority · track · 30EPSS 0.002 · 15 %ileEUUSEPSS · scored 2026-10-27
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4.7–7.5
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (12)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- GHSA-mwmh-mq4g-g6grElectron: Registry key path injection in app.setAsDefaultProtocolClient on Windows2026-04-03ghsa · osvUS
### Impact 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. ### Workarounds Validate the protocol name matches `/^[a-zA-Z][a-zA-Z0-9+.-]*$/` before passing it to `app.setAsDefaultProtocolClient()`. ### 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](mailto:security@electronjs.org)
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (4)
External citations — patches, advisories, analysis.
- https://github.com/electron/electron/releasesPatchcnnvd
- https://github.com/electron/electron/security/advisories/GHSA-mwmh-mq4g-g6grcnnvd
- https://github.com/electron/electron/security/advisories/GHSA-mwmh-mq4g-g6grenisa_euvd
- https://github.com/electron/electron/security/advisories/GHSA-mwmh-mq4g-g6grVendor Advisorynvd
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