CVE-2026-121137 in Chrome
Summary
by MITRE • 11/03/2026
Type confusion in DevTools in Google Chrome prior to 157.0.8103.38 allowed a remote attacker leveraging social engineering to execute arbitrary code inside the sandbox via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 11/04/2026
The vulnerability identified as a type confusion issue within the DevTools component of Google Chrome prior to version 157.0.8103.38 represents a significant memory safety flaw that undermines the browser's sandboxing mechanisms. Type confusion vulnerabilities occur when an application incorrectly handles data types, leading it to interpret a value as one type while treating it as another in subsequent operations. In this specific instance, the DevTools interface, which is primarily intended for debugging and development purposes, was susceptible to misinterpretation of object structures during execution. This flaw allows an attacker who can trick a user into visiting a maliciously crafted HTML page to exploit the discrepancy between expected and actual data types within the browser's internal memory management systems.
The operational impact of this vulnerability is severe because it facilitates arbitrary code execution with high privileges relative to the sandboxed environment. Typically, web content runs in a restricted sandbox that limits its ability to interact directly with the underlying operating system or other processes. However, by leveraging the type confusion flaw within DevTools, an attacker can bypass these restrictions and execute commands outside of this protective boundary. This capability effectively neutralizes one of the primary security defenses employed by modern browsers, allowing for potential data theft, installation of malware, or further lateral movement within a compromised system. The requirement for social engineering indicates that direct remote exploitation without user interaction is not feasible; instead, an attacker must deceive the victim into loading specific content, often through phishing campaigns or malicious advertisements.
From a classification perspective, this vulnerability aligns with CWE-843, which describes access to incorrect type via reference, and falls under the ATT&CK technique of T1059 Command and Scripting Interpreter if it leads to script execution within the host environment. The Chromium security team has classified this issue as High severity due to its potential for remote code execution and the critical nature of maintaining sandbox integrity in a widely used web browser. Such flaws are particularly dangerous because they exploit trusted components like DevTools, which may have elevated permissions or access to internal APIs that standard webpage scripts do not possess.
Mitigation strategies primarily involve immediate patching by updating Google Chrome to version 157.0.8103.38 or later, where the type confusion logic has been corrected and memory safety checks are enforced more rigorously. For organizations unable to update immediately, network-level controls such as web filtering proxies can be configured to block access to known malicious domains hosting exploit kits. Additionally, enabling strict Content Security Policy headers on internal websites and disabling unnecessary DevTools features in production environments can reduce the attack surface. Users should remain vigilant against unsolicited links or downloads that prompt them to enable developer tools or interact with unfamiliar interfaces, as these are common vectors for social engineering attacks targeting this specific class of vulnerabilities.