CVE-2026-70603

### Impact `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. Node's `fs` APIs already reject paths containing null bytes, so apps that call `fs.existsSync()`, `fs.stat()`, or similar before `shell.openPath()` are not affected. Apps that do not call `shell.openPath()` with untrusted input are not affected. ### Workarounds Reject any path containing a null byte before passing it to `shell.openPath()`: ```js if (filePath.includes('\0')) throw new Error('invalid path'); ``` ### Fixed Versions * `42.0.0-beta.1` * `41.1.1` * `40.9.0` * `39.8.6` ### For more information If you have any questions or comments about this advisory, email us at [security@electronjs.org](mailto:security@electronjs.org)