CVE-2026-113321 in Chrome
Summary
by MITRE • 10/21/2026
Use after free in Extensions in Google Chrome prior to 156.0.8078.47 allowed a remote attacker to execute arbitrary code inside the sandbox via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 10/21/2026
The vulnerability identified as a use-after-free condition within the Extensions component of Google Chrome prior to version 156.0.8078.47 represents a critical memory management flaw that undermines the browser's sandboxing mechanisms. This specific class of error occurs when an application continues to use a pointer after the memory it points to has been freed, leading to undefined behavior that can be exploited by malicious actors. In this instance, the defect resides in how Chrome handles resources associated with its extension system, which is designed to isolate web content and limit the privileges granted to third-party code. When an attacker crafts a specific HTML page that triggers the premature deallocation of memory while references to that memory are still active within the extension runtime, it creates a window for exploitation where the browser may interpret freed heap data as valid executable instructions or control structures.
From a technical perspective, this vulnerability aligns with CWE-416, which defines use-after-free errors resulting from improper management of dynamically allocated memory. The attack vector involves a remote adversary hosting a malicious webpage that leverages JavaScript to interact with Chrome extensions in a way that forces the browser to release certain objects while maintaining internal references to them. By carefully crafting the sequence of events and manipulating heap layout, an attacker can overwrite freed memory with controlled data structures. This allows for arbitrary code execution within the context of the compromised process. Although Google Chrome employs robust sandboxing techniques such as site isolation and restricted permissions to mitigate the impact of browser vulnerabilities, a successful exploitation of this use-after-free flaw could potentially allow an attacker to escape these restrictions or execute commands with elevated privileges relative to other tabs or processes, depending on the specific extension's granted permissions and the state of the heap at the time of exploitation.
The operational impact of this vulnerability is significant because it enables remote code execution without user interaction beyond visiting a malicious site. This falls under the MITRE ATT&CK technique T1203, which covers Exploitation for Client Execution, specifically targeting web browsers as the attack vector. The ability to execute arbitrary code inside the sandbox means that an attacker could install malware, steal sensitive data such as cookies and session tokens, or use the compromised browser as a pivot point for further network attacks. Given that Chrome is one of the most widely used web browsers globally, this vulnerability poses a substantial risk to user privacy and system integrity if left unpatched. The severity rating of Medium reflects the complexity required to reliably exploit the flaw in modern versions with mitigations like heap randomization and guard pages, but it remains dangerous due to its remote nature and potential for privilege escalation within the browser environment.
To mitigate this vulnerability, users must immediately update Google Chrome to version 156.0.8078.47 or later, where the memory management logic in the Extensions component has been corrected to prevent dangling pointers from being dereferenced after deallocation. Security administrators should ensure that automatic updates are enabled for all endpoints within their organization to minimize the window of exposure. Additionally, implementing strict content security policies and restricting the installation of unverified extensions can reduce the attack surface available to potential exploiters. Monitoring browser logs for unusual memory access patterns or unexpected process behavior may also aid in detecting attempted exploitation activities before full compromise occurs. Regular patching cycles are essential as new variants of this vulnerability class continue to emerge, requiring vigilant maintenance of software dependencies and runtime environments.