CVE-2026-93373 in Chrome
Summary
by MITRE • 09/18/2026
Use after free in Extensions in Google Chrome prior to 153.0.8010.52 allowed a remote attacker to execute arbitrary code outside the sandbox via a crafted Chrome extension. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 09/18/2026
The vulnerability identified as a use-after-free condition within the Extensions subsystem of Google Chrome prior to version 153.0.8010.52 represents a critical memory management error that compromises the integrity and confidentiality of the browser environment. This flaw arises when an extension attempts to access or manipulate objects in memory after they have been freed, leading to undefined behavior that can be exploited by malicious actors. The severity is classified as High within the Chromium security framework due to its potential for remote code execution outside the confines of the sandboxed extension context. Such vulnerabilities are particularly dangerous because extensions often operate with elevated privileges compared to standard web pages, and a successful exploit could allow an attacker to bypass these restrictions entirely.
From a technical perspective, use-after-free errors occur when a pointer continues to be used after the memory it points to has been deallocated. In the context of Chrome Extensions, this typically involves complex interactions between JavaScript code running in the extension's background pages or content scripts and native C++ components that handle rendering, networking, or DOM manipulation. If an attacker can craft a specific sequence of actions within a maliciously designed extension, they may trigger a state where memory is freed but references to it remain active. By carefully controlling the allocation patterns following the free operation, an attacker can overwrite these dangling pointers with controlled data structures, effectively gaining arbitrary read and write capabilities in the process space hosting the browser engine.
The operational impact of this vulnerability extends beyond simple data corruption or application crashes. Because Chrome employs a multi-process architecture designed to isolate web content from system resources, successful exploitation allows code execution outside the sandboxed renderer processes. This means an attacker could potentially execute arbitrary commands on the underlying operating system with the privileges of the user running the browser. The attack vector is remote in nature, as it requires only that a victim visits a webpage or interacts with a malicious extension hosted online. Once triggered, the exploit chain typically involves achieving code execution within the sandboxed environment and then leveraging this memory corruption to escape into higher-privilege processes such as the browser utility process or main browser process.
This vulnerability aligns closely with Common Weakness Enumeration identifier CWE-416, which describes use after free scenarios resulting from improper management of dynamic memory allocation. Furthermore, in terms of tactical classification under the MITRE ATT&CK framework, this flaw facilitates techniques associated with initial access and privilege escalation through exploitation of client-side software vulnerabilities. The ability to execute code outside the sandbox directly supports lateral movement within a compromised system if the browser is used as an entry point for further attacks against networked resources or internal applications accessed via the same user session.
Mitigation strategies primarily involve immediate patching to version 153.0.8010.52 or later, which includes fixes that enforce stricter memory management protocols and add bounds checking within the extension handling subsystems. Organizations should ensure automated update mechanisms are enabled for all Chrome installations across their infrastructure to minimize exposure windows. Additionally, administrators can restrict the installation of third-party extensions through group policy settings to reduce the attack surface presented by potentially malicious or poorly coded add-ons. Security monitoring tools should be configured to detect anomalous behavior indicative of memory corruption exploits, such as unusual network connections originating from browser processes or unexpected privilege changes within extension-related services. Regular audits of installed extensions and removal of unused ones further reduces the likelihood of encountering a crafted exploit targeting this specific flaw.