CVE-2026-102299 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 confusion vulnerabilities occur when an application incorrectly assumes that a variable or object contains data of one specific type while it actually holds data of another incompatible type. In the context of V8, this typically involves the engine's Just-In-Time (JIT) compiler optimizing code based on assumed types during execution. When these assumptions are violated due to crafted input, the runtime may perform operations such as memory reads or writes using incorrect offsets or sizes derived from the misinterpreted data structure. This discrepancy allows an attacker to manipulate how the browser interprets memory layouts, effectively bypassing the strict type safety that V8 is designed to enforce during script execution.
From a technical perspective, this flaw enables arbitrary code execution within the Chrome sandbox environment. The sandbox architecture in modern browsers relies on process isolation and restricted permissions to limit the damage caused by exploits originating from web content. However, when a type confusion vulnerability allows for out-of-bounds memory access or heap corruption, it can be leveraged to achieve arbitrary read/write primitives. These primitives are foundational steps in an exploitation chain that allow attackers to overwrite function pointers, return addresses, or other critical control flow data structures within the browser process. By carefully crafting HTML pages and JavaScript payloads, a remote attacker can trigger these memory corruptions during page rendering or script evaluation, ultimately gaining the ability to execute arbitrary machine code with the privileges of the compromised browser instance.
The operational impact of this vulnerability is severe due to its potential for remote exploitation without user interaction beyond visiting a malicious website. As classified under CWE-843, which covers access of incorrect type assumption, such flaws are particularly dangerous because they often bypass high-level security abstractions. The Chromium project has assigned this issue a High severity rating, reflecting the ease with which it can be weaponized for drive-by download attacks or further privilege escalation attempts within the host system if sandbox escape techniques are combined with this initial foothold. Attackers can utilize this vulnerability to install malware, steal sensitive user data such as cookies and session tokens, or establish persistent backdoors on victim systems by exploiting the trust relationship between the browser and local resources.
Mitigation strategies primarily involve immediate software updates to ensure that all instances of Google Chrome are upgraded to version 154.0.8037.92 or later, where these type checking mechanisms have been hardened and corrected. For organizations managing large fleets of devices, automated patch management systems should be configured to prioritize this update due to the active exploitation potential associated with high-severity V8 vulnerabilities. Additionally, security teams can employ browser hardening techniques such as disabling JavaScript execution for untrusted sites or utilizing content security policies that restrict inline scripts and external resource loading where feasible. Monitoring network traffic for suspicious payloads attempting to exploit known memory corruption patterns in web applications can also provide an additional layer of defense against attempts to leverage this specific type confusion flaw before patches are fully deployed across all endpoints.