CVE-2026-118316 in Chrome
Summary
by MITRE • 10/28/2026
Improper input validation in V8 in Google Chrome prior to 156.0.8078.73 allowed a remote attacker to potentially execute arbitrary code outside the sandbox via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 10/28/2026
The vulnerability identified as an improper input validation flaw within the V8 JavaScript engine, which powers Google Chrome prior to version 156.0.8078.73, represents a critical breach in the browser's memory safety guarantees. This specific defect allows for potential arbitrary code execution outside of the sandboxed environment that typically isolates web content from the underlying operating system and user data. The root cause lies in insufficient checks performed on input parameters during the parsing or compilation phases of JavaScript code processed by V8, enabling a remote attacker to manipulate internal state variables or memory structures in unintended ways.
From a technical perspective, this flaw falls under the category of CWE-20 Improper Input Validation and is closely associated with CWE-119 Memory Corruption vulnerabilities such as buffer overflows or type confusion errors common in high-performance JIT compilers like V8. When an attacker crafts a malicious HTML page containing specially constructed JavaScript payloads, they can exploit these validation gaps to corrupt memory structures. This corruption may lead to arbitrary read/write primitives, which are foundational steps for achieving full code execution within the context of the browser process or potentially escaping it entirely depending on the specific exploitation path and system architecture.
The operational impact of this vulnerability is severe due to its remote nature and lack of user interaction requirements beyond visiting a malicious website. An attacker can host the crafted HTML page on a web server and lure users into accessing it, often through social engineering tactics or drive-by download techniques. Successful exploitation could result in complete compromise of the victim's system, including theft of sensitive data such as credentials, cookies, and personal information stored by the browser. Furthermore, because the vulnerability allows execution outside the sandbox, it bypasses many modern security mitigations designed to limit the blast radius of web-based attacks, potentially leading to persistent malware installation or lateral movement within a network if the compromised machine is part of an enterprise environment.
This incident aligns with several techniques in the MITRE ATT&CK framework, particularly T1204 User Execution for initial access via malicious content and T1059 Command and Scripting Interpreter for executing arbitrary code through JavaScript engines. The ability to escape the sandbox also relates to privilege escalation vectors where an attacker gains higher-level system privileges than intended by the browser's security model.
To mitigate this risk, organizations must ensure that all instances of Google Chrome are updated to version 156.0.8078.73 or later immediately upon availability. For enterprise environments, deploying centralized patch management solutions can help automate the distribution and installation of these updates across endpoints. Additionally, implementing application control policies and restricting JavaScript execution in untrusted zones can provide an additional layer of defense against exploitation attempts. Security awareness training should also be conducted to educate users about the risks of visiting unfamiliar or suspicious websites, although technical controls remain the primary line of defense against such automated attacks. Regular monitoring for indicators of compromise related to browser-based exploits is recommended to detect any potential successful intrusions that may have occurred prior to patching.