CVE-2026-70603 Electron: shell.openPath path validation bypass via embedded null byte
Attackers can bypass path validation in Electron apps using null bytes to open unintended files, potentially leading to code execution or data exposure.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-70603?
CVE-2026-70603 is a medium-severity path traversal vulnerability in Electronjs Electron, published on 5 Aug 2026. It can only be exploited from the same machine or local network, 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 39.8.6, 40.9.0, 41.1.1, and 42.0.0-beta.1, shell.openPath() did not reject paths containing embedded null bytes. Apps that perform string-only validation of file paths, for example checking the file extension, before passing them to shell.openPath() could be bypassed, allowing an attacker-controlled path to open a different file than the one that passed validation. Apps are only affected if they pass paths derived from untrusted input to shell.openPath() and rely on string-based validation without a filesystem check. This issue is fixed in versions 39.8.6, 40.9.0, 41.1.1, and 42.0.0-beta.1.
Which versions are affected by CVE-2026-70603?
8 open source packages ship an affected version, including electron. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
electron npm | All versions | 39.8.6 |
electron npm | All versions | 39.8.6 |
electron npm | From 40.0.0-alpha.1 | 40.9.0 |
electron npm | From 40.0.0-alpha.1 | 40.9.0 |
electron npm | From 41.0.0-alpha.1 | 41.1.1 |
electron npm | From 41.0.0-alpha.1 | 41.1.1 |
2 more packages
electron npm | From 42.0.0-alpha.1 | 42.0.0-beta.1 |
electron npm | From 42.0.0-alpha.1 | 42.0.0-beta.1 |
Products include Electronjs Electron.
How do I fix CVE-2026-70603?
Upgrade electron to a fixed version for your release line: 39.8.6, 40.9.0, 41.1.1 or 42.0.0-beta.1.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-70603 being exploited?
There is no known exploitation of CVE-2026-70603 in the wild and no public exploit code.
Other vulnerabilities in Electronjs Electron
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- 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-5c9j-mhmv-5xgx.