CVE-2026-70606 Electron: ProtocolResponse.url reuses the default session cache instead of the registering session
Electron apps using custom protocol handlers may leak cached data across isolated sessions if the session is not explicitly specified in the response.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-70606?
CVE-2026-70606 is a medium-severity vulnerability in Electronjs Electron, published on 5 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 40.10.6, 41.9.1, 42.5.1, and 43.0.0, when a custom protocol handler returned a ProtocolResponse with a url and no session, Electron made the upstream request through defaultSession instead of the session that handled the protocol. A cached response could then be reused across otherwise isolated session partitions. Apps that use ProtocolResponse.url, omit ProtocolResponse.session, and rely on separate sessions to isolate content are affected. This issue is fixed in versions 40.10.6, 41.9.1, 42.5.1, and 43.0.0.
Weakness: CWE-668
Which versions are affected by CVE-2026-70606?
8 open source packages ship an affected version, including electron. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
electron npm | From 40.0.0-alpha.1 | 40.10.6 |
electron npm | From 40.0.0-alpha.1 | 40.10.6 |
electron npm | From 41.0.0-alpha.1 | 41.9.1 |
electron npm | From 41.0.0-alpha.1 | 41.9.1 |
electron npm | From 42.0.0-alpha.1 | 42.5.1 |
electron npm | From 42.0.0-alpha.1 | 42.5.1 |
2 more packages
electron npm | From 43.0.0-alpha.1 | 43.0.0 |
electron npm | From 43.0.0-alpha.1 | 43.0.0 |
Products include Electronjs Electron.
How do I fix CVE-2026-70606?
Upgrade electron to a fixed version for your release line: 40.10.6, 41.9.1, 42.5.1 or 43.0.0.
Is CVE-2026-70606 being exploited?
There is no known exploitation of CVE-2026-70606 in the wild and no public exploit code.
Other vulnerabilities in Electronjs Electron
- CVE-2017-16151 Chromium Remote Code Execution in electron
- CVE-2018-1000118 Electron protocol handler browser vulnerable to Command Injection
- CVE-2026-34780 Electron: Context Isolation bypass via contextBridge VideoFrame transfer
- CVE-2026-102676 Electron: <webview> can enable Node.js integration in Web Workers despite embedder restrictions
- CVE-2026-102673 Electron drops inherited HTML sandbox restrictions for popups opened through OpenURLFromTab
Sources
Also known as GHSA-r4w5-6pfg-jxp5.