CVE-2026-118341 in Chrome
Summary
by MITRE • 10/28/2026
Use after free in Modularization in Google Chrome prior to 156.0.8078.73 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 • 10/28/2026
The vulnerability identified as a use-after-free error within the Modularization component of Google Chrome prior to version 156.0.8078.73 represents a critical memory management flaw that compromises the browser's integrity and security posture. This specific defect arises when an object is deallocated from memory but continues to be referenced by other parts of the application, leading to undefined behavior upon subsequent access. In the context of web browsers, such errors are particularly dangerous because they can often be triggered through standard web content rendering processes, allowing attackers to manipulate how the browser handles internal data structures during page parsing and execution.
From a technical perspective, this vulnerability falls under the Common Weakness Enumeration category CWE-416, which defines use-after-free conditions where memory is freed but still accessed by the program logic. The Modularization subsystem in Chromium is responsible for managing module dependencies and loading scripts efficiently to optimize performance. When an attacker crafts a malicious HTML page that triggers specific timing conditions or state changes within this system, they can cause the browser to release memory associated with certain objects while retaining pointers to those same locations. Subsequent operations on these dangling pointers allow the attacker to write arbitrary data into previously freed memory regions, effectively gaining control over critical execution flows and internal object states.
The operational impact of this vulnerability is severe due to its potential for remote code execution within a sandboxed environment. Although Chrome employs multiple layers of defense including site isolation and sandboxing to limit the damage caused by exploits, successful exploitation of this use-after-free flaw can allow an attacker to bypass these protections. By carefully crafting heap layouts and exploiting race conditions or specific object lifecycles, an adversary can achieve arbitrary read-write primitives that facilitate code execution inside the renderer process sandbox. This capability enables the loading of malicious payloads, data exfiltration, or further lateral movement within a compromised system if additional vulnerabilities are chained together to escape the browser's security boundaries.
This incident aligns with several techniques documented in the MITRE ATT&CK framework, particularly those related to initial access and execution phases such as T1189 Drive-by Compromise and potentially T1203 Exploitation for Client Execution. The attack vector relies on a remote attacker delivering malicious content via a crafted HTML page, which is then rendered by the victim's browser without any user interaction beyond visiting the site or clicking a link. This highlights the importance of keeping browsers updated to mitigate risks associated with complex web-based attacks that target rendering engines and internal module management systems.
To mitigate this risk, organizations and individual users must ensure that Google Chrome is upgraded to version 156.0.8078.73 or later immediately upon availability. This update contains patches for the underlying memory handling logic in the Modularization component, ensuring that objects are properly tracked and freed only when no longer referenced by any active pointers. Additionally, security teams should enforce strict content security policies to restrict inline scripts and untrusted sources where possible, reducing the attack surface available to potential exploit developers. Regular monitoring of browser update notifications and automated patch management systems are essential practices to maintain resilience against such high-severity vulnerabilities in widely used web applications.