CVE-2026-121224 in Chrome
Summary
by MITRE • 11/03/2026
Security issue in Desktop in Google Chrome on on Mac prior to 157.0.8103.38 allowed a remote attacker who had compromised the renderer process to potentially execute arbitrary code outside the sandbox via crafted network traffic. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 11/03/2026
The vulnerability identified in Google Chrome for macOS, specifically affecting versions prior to 157.0.8103.38, represents a critical breach of the browser's isolation boundaries. This flaw resides within the Desktop subsystem and exploits conditions where a remote attacker who has already achieved code execution within a compromised renderer process can escalate privileges beyond the sandbox environment. The Chromium security team classified this issue with a High severity rating due to its potential for arbitrary code execution outside the protective confines of the sandbox, which is fundamental to modern browser security architectures designed to contain malicious activity within individual tabs or processes.
From a technical perspective, the core flaw involves an improper handling of network traffic that interacts with desktop-level components. When a renderer process, typically restricted by strict permissions and memory isolation, receives crafted network data, it triggers a logic error in how the Desktop subsystem validates or processes this input. This mismanagement allows the malicious payload to bypass standard sandboxing mechanisms such as Seccomp-BPF filters on Linux or similar access control lists on macOS. The attacker leverages specific sequences of network packets that exploit race conditions or memory corruption vulnerabilities within the desktop integration layer, effectively bridging the gap between the untrusted renderer context and trusted system resources.
The operational impact of this vulnerability is severe because it undermines one of the primary defenses against drive-by download attacks and malicious web content exploitation. If an attacker can successfully execute arbitrary code outside the sandbox, they gain unrestricted access to the underlying operating system. This capability allows for full system compromise, including the ability to install persistent malware, exfiltrate sensitive data such as credentials or financial information, modify system configurations, and establish a foothold for further lateral movement within a networked environment. The risk is particularly acute given that users frequently visit untrusted websites where attackers may embed exploit code designed to trigger this specific flaw through automated delivery mechanisms.
This vulnerability aligns with Common Weakness Enumeration (CWE) categories such as CWE-78 Improper Neutralization of Special Elements used in an OS Command, often referred to as OS Command Injection, or potentially CWE-120 Buffer Overflow if memory corruption is involved in the exploitation chain. In terms of the MITRE ATT&CK framework, this exploit maps directly to Tactic 1: Execution and Technique T1059 Command and Scripting Interpreter, specifically involving code execution outside a sandboxed environment which facilitates privilege escalation from low-integrity processes to high-integrity system contexts. It also relates to Defense Evasion techniques where attackers bypass security software by escaping restricted environments.
Mitigation strategies primarily involve immediate patching of the Google Chrome browser on all affected macOS devices to version 157.0.8103.38 or later, which contains the necessary code fixes to validate input correctly and enforce stricter boundaries between renderer processes and desktop components. Organizations should ensure that automatic updates are enabled for browsers across their endpoints to minimize exposure windows. Additionally, implementing application whitelisting policies can restrict the execution of unauthorized binaries even if an attacker manages to escape the sandbox, thereby adding a layer of defense-in-depth. Network monitoring solutions should also be configured to detect anomalous network traffic patterns originating from browser processes that attempt to communicate with unexpected external endpoints or exhibit behaviors consistent with exploit delivery mechanisms.