CVE-2026-70603 in Electron
Summary
by MITRE • 08/05/2026
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.
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Analysis
by VulDB Data Team • 08/05/2026
The vulnerability in Electron's shell.openPath() function represents a critical path traversal flaw that undermines application security through improper input validation mechanisms. This issue affects multiple major versions of the framework and stems from the failure to properly sanitize file paths containing embedded null bytes before processing them through the operating system's file opening mechanisms. The technical root cause lies in the absence of proper null byte validation within the shell.openPath() implementation, which allows attackers to manipulate file paths in ways that bypass conventional string-based validation checks that applications might employ. When applications perform basic extension checking or other string-only validations before passing paths to shell.openPath(), they inadvertently create a security gap where malicious actors can exploit the null byte handling to redirect file operations to unintended targets.
The operational impact of this vulnerability extends beyond simple path manipulation, creating potential for arbitrary file access and execution scenarios that align with common attack patterns documented in the attack mitigation framework. This flaw particularly affects applications that implement trust boundaries based on string validation alone, without incorporating proper filesystem verification mechanisms. From a cybersecurity perspective, this vulnerability represents a classic example of how insufficient input sanitization can lead to privilege escalation and unauthorized system access. The issue is particularly dangerous because it leverages the fundamental trust placed in string-based validation schemes that many developers consider sufficient for basic security requirements.
Security professionals should recognize this vulnerability through its alignment with common CWE classifications related to improper input validation and buffer overflows, specifically CWE-170 which addresses issues with null bytes in strings. The attack surface is broad as any application using Electron's shell.openPath() function with untrusted input sources becomes potentially vulnerable, particularly those implementing client-side file path validation without comprehensive filesystem checks. Organizations should treat this vulnerability as a critical security concern requiring immediate remediation across all affected Electron applications, especially those handling user-provided file paths or operating in environments where input sanitization is not rigorously enforced.
The mitigation strategy requires immediate version upgrades to the patched releases 39.8.6, 40.9.0, 41.1.1, and 42.0.0-beta.1 which implement proper null byte rejection mechanisms in shell.openPath() function calls. Additionally, developers should adopt defensive programming practices that include comprehensive input validation beyond simple string checks, implementing filesystem verification layers before any path processing occurs. Security teams should also consider implementing runtime monitoring for suspicious file access patterns and establishing more robust input sanitization procedures across all applications utilizing Electron frameworks, particularly those handling user-provided file paths or operating system-level file operations. The vulnerability demonstrates the critical importance of proper input validation in preventing exploitation of seemingly benign functionality that can be weaponized through careful manipulation of string representations.