CVE-2026-113023 in Chrome
Summary
by MITRE • 10/21/2026
Improper input validation in Extensions in Google Chrome prior to 156.0.8078.47 allowed a remote attacker to potentially execute arbitrary code outside the sandbox via a crafted HTML page. (Chromium security severity: Low)
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Analysis
by VulDB Data Team • 10/21/2026
The vulnerability identified as an improper input validation flaw within the Extensions component of Google Chrome prior to version 156.0.8078.47 represents a significant breach in browser isolation mechanisms. This specific defect allows for potential arbitrary code execution outside the standard security sandbox, which is designed to restrict untrusted web content from accessing system resources directly. The root cause lies in insufficient sanitization or type checking of inputs processed by extension APIs, enabling an attacker to manipulate internal data structures or function calls that are not adequately protected by boundary checks. This failure in input validation creates a pathway for malicious actors to bypass the sandbox boundaries, effectively elevating their privileges from restricted web context to full system access depending on the specific execution environment and user permissions.
From a technical perspective, this flaw aligns with CWE-20 Improper Input Validation, where software fails to verify that incoming data meets expected criteria before processing it. In the context of browser extensions, which often have elevated privileges compared to standard web pages, such validation errors are particularly dangerous. An attacker can craft a specific HTML page containing malicious scripts or payloads designed to exploit this gap in logic. When a user visits this crafted page while having relevant extensions installed and enabled, the extension processes the malformed input without proper checks. This allows the execution of arbitrary commands within the context of the browser process, which may have broader access rights than the sandboxed renderer process. The severity is classified as Low by Chromium security standards because successful exploitation typically requires user interaction, such as visiting a malicious site or opening a specific file, and depends on the presence of vulnerable extensions with high privileges.
The operational impact of this vulnerability extends beyond simple code execution within the browser environment. If an attacker successfully exploits this flaw to escape the sandbox, they gain the ability to interact directly with the operating system. This can lead to data theft, installation of persistent malware, or use of the compromised machine as part of a botnet. The attack vector is classified under ATT&CK technique T1059 Command and Scripting Interpreter, specifically through browser-based execution mechanisms like JavaScript or extension APIs. Furthermore, it relates to ATT&CK tactic TA0004 Privilege Escalation, as escaping the sandbox effectively grants higher privileges than originally intended for web content. The risk is amplified by the widespread use of extensions that often request broad permissions, making them attractive targets for exploitation if their input handling logic is flawed.
Mitigation strategies primarily involve updating Google Chrome to version 156.0.8078.47 or later, where these validation checks have been strengthened and patched. Users should ensure automatic updates are enabled to receive security patches promptly. Additionally, administrators can reduce the attack surface by auditing installed extensions and removing any that are unnecessary or originate from untrusted sources. Implementing strict content security policies for internal extension pages and minimizing the permissions requested by extensions can further limit the potential impact of such vulnerabilities. Regular monitoring of browser behavior and employing endpoint detection and response tools can also help identify anomalous activities resulting from successful exploitation attempts, providing an additional layer of defense against sandbox escape attacks.