CVE-2026-102326 in Chrome
Summary
by MITRE • 09/29/2026
Type confusion in V8 in Google Chrome prior to 154.0.8037.92 allowed a remote attacker 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 • 09/29/2026
The vulnerability identified as a type confusion issue within the V8 JavaScript engine, which powers Google Chrome prior to version 154.0.8037.92, represents a critical failure in memory safety and runtime type checking mechanisms. Type confusions occur when an application incorrectly assumes that a variable or object is of one data type while it actually holds another, leading to unpredictable behavior during execution. In the context of V8, this flaw likely stems from improper handling of JavaScript objects where the engine fails to validate the actual memory layout against the expected structural definition before performing operations. This discrepancy allows an attacker who crafts a malicious HTML page containing specific JavaScript payloads to manipulate how the browser interprets object properties and values in memory. The severity is classified as High by Chromium security standards because it directly compromises the integrity of the execution environment, providing a pathway for arbitrary code execution that bypasses standard safety checks.
From a technical perspective, this vulnerability exploits weaknesses in the Just-In-Time (JIT) compilation process or garbage collection routines where type information might be cached or optimized away without sufficient verification during subsequent accesses. When V8 optimizes JavaScript code for performance, it often relies on hidden classes to track object shapes and types. If an attacker can trigger a state change that alters these hidden classes in an unexpected way, the engine may read or write memory using incorrect offsets or sizes associated with different data structures. This misalignment enables the overwriting of critical pointers or function addresses within the heap space. Such manipulation is particularly dangerous because it allows for precise control over program flow, which can be leveraged to bypass stack-based protections and execute shellcode in a controlled manner.
The operational impact of this vulnerability is severe due to its potential for remote code execution via a crafted HTML page. An attacker does not need physical access or user interaction beyond visiting the malicious site, making it suitable for drive-by download attacks. Once arbitrary code is executed within the browser sandbox, the immediate consequence is the compromise of the client-side environment. Although Chrome employs multiple layers of defense such as Site Isolation and sandboxing to limit the damage, a successful exploitation can still lead to data exfiltration, session hijacking, or further lateral movement if additional vulnerabilities are chained together. The ability to execute code inside the sandbox means that sensitive information stored in local storage, cookies, or memory buffers becomes accessible to malicious scripts, undermining user privacy and security posture significantly.
To mitigate this risk, organizations must ensure that all instances of Google Chrome are updated to version 154.0.8037.92 or later immediately upon availability. This patch includes fixes for the underlying type checking logic in V8, ensuring that object types are validated correctly before memory operations occur. For enterprise environments, implementing strict content security policies and restricting script execution from untrusted sources can reduce the attack surface by preventing the loading of malicious HTML pages. Additionally, enabling automatic updates ensures that users receive these critical patches without manual intervention. Security teams should also monitor for indicators of compromise related to V8 exploitation techniques, such as unusual memory allocation patterns or attempts to access restricted APIs, which may signal active probing for this vulnerability in the wild.
This incident aligns with Common Weakness Enumeration (CWE) category CWE-843, Access of Resource Using Incompatible Type, and reflects a failure in proper type validation that is characteristic of many high-severity browser vulnerabilities. It also maps to MITRE ATT&CK techniques involving client-side code execution, specifically T1059 Command and Scripting Interpreter through JavaScript abuse. Understanding these mappings helps security professionals categorize the threat correctly within broader frameworks and prioritize remediation efforts based on industry-standard risk assessments. The resolution of this issue underscores the importance of rigorous testing in engine development and continuous monitoring for similar patterns in other web technologies to prevent future exploits that could lead to full system compromise.