Electron: Registry key path injection in app.setAsDefaultProtocolClient on Windows
Published 3 Apr 2026 · Updated 6 Apr 2026
Affected packages
- Affected
- <38.8.6
- Fixed in
- 38.8.6
npm install electron@38.8.6- Affected
- >=39.0.0-alpha.1 <39.8.1
- Fixed in
- 39.8.1
npm install electron@39.8.1- Affected
- >=40.0.0-alpha.1 <40.8.1
- Fixed in
- 40.8.1
npm install electron@40.8.1- Affected
- >=41.0.0-alpha.1 <41.0.0
- Fixed in
- 41.0.0
npm install electron@41.0.0Details
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
41.0.040.8.139.8.138.8.6
For more information
If there are any questions or comments about this advisory, please email [security@electronjs.org](mailto:security@electronjs.org)
Is GHSA-mwmh-mq4g-g6gr in any of your client repos?
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References
Advisory data from OSV.dev (opens OSV.dev in a new tab), refreshed daily.