CVE-2026-102323 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 flaw 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 belongs to one data type while it actually contains another, leading to undefined behavior during execution. In the context of V8, this typically involves the misinterpretation of JavaScript objects' internal structures or hidden classes, which are used by the engine for optimization and property access. When such a confusion is triggered via a crafted HTML page served from a remote server, it allows an attacker to manipulate how memory addresses and values are read or written, effectively bypassing the strict isolation boundaries that V8 enforces between different execution contexts.
From a technical perspective, this flaw exploits weaknesses in the Just-In-Time (JIT) compilation process where type inference may become stale or incorrect under specific conditions involving polymorphic functions or complex object graphs. By carefully constructing JavaScript code within an HTML page, an attacker can force the V8 engine to treat a pointer as a different data type, such as interpreting a heap address as an integer or vice versa. This misinterpretation enables arbitrary read and write primitives, which are foundational for achieving full sandbox escape. The Chromium security severity rating of High reflects the significant risk posed by this vulnerability, as it directly compromises the integrity of the browser's secure execution environment without requiring user interaction beyond visiting a malicious webpage.
The operational impact of exploiting this type confusion is severe, allowing remote code execution within the Chrome sandbox. While modern browsers employ multiple layers of defense such as Control Flow Integrity (CFI), memory protection flags like DEP and ASLR, and process isolation to mitigate exploitation, successfully leveraging this vulnerability can lead to a complete compromise of the user's system if subsequent steps in an exploit chain are executed. An attacker could use these primitives to bypass sandbox restrictions, inject malicious payloads into trusted processes, or escalate privileges on the host operating system. This capability transforms a simple web browsing session into a potential entry point for malware installation, data theft, and further network infiltration, posing substantial risks to both individual users and enterprise environments relying on Chrome for secure internet access.
Mitigation strategies primarily involve updating Google Chrome to version 154.0.8037.92 or later, where the underlying type checking logic in V8 has been corrected to prevent the misinterpretation of object types during runtime operations. Organizations should ensure that automatic updates are enabled for all endpoints running affected versions of the browser to minimize exposure windows. Additionally, implementing strict Content Security Policy (CSP) headers can help mitigate some aspects of web-based attacks by restricting the sources from which scripts and other resources can be loaded, although this does not directly fix the underlying engine vulnerability. Security teams should also monitor for indicators of compromise related to known exploitation techniques associated with V8 type confusions, such as unusual memory access patterns or attempts to escape sandboxed environments.
This incident aligns with Common Weakness Enumeration (CWE) category CWE-843, which describes Access of Incorrect Type, and is closely related to CWE-120 Buffer Overflow if the misinterpretation leads to out-of-bounds writes. In terms of attack tactics, this vulnerability facilitates techniques described in MITRE ATT&CK framework under Tactic TA0005 Defense Evasion, specifically subtechniques involving sandbox escape or process injection. Understanding these classifications helps security professionals prioritize patching efforts and enhance monitoring capabilities against similar engine-level vulnerabilities that threaten the foundational trust model of web browsers.