CVE-2026-121044 in Chrome
Summary
by MITRE • 11/03/2026
Use after free in Layout in Google Chrome prior to 157.0.8103.38 allowed a remote attacker to execute arbitrary code inside the sandbox via a crafted HTML page. (Chromium security severity: High)
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 11/03/2026
The vulnerability identified as a use-after-free condition within the Layout component of Google Chrome prior to version 157.0.8103.38 represents a critical memory safety failure that undermines the browser's core isolation mechanisms. This specific flaw occurs when an object in the layout tree is freed from memory while references to it are still retained and subsequently accessed by the rendering engine. In modern web browsers, the Layout phase is responsible for calculating the geometric properties of elements on a page, such as position and size, which requires precise manipulation of internal data structures. When these structures are corrupted due to premature deallocation, the browser's memory manager may interpret stale pointers as valid objects, leading to undefined behavior that can be exploited by malicious actors.
From an offensive security perspective, this type of vulnerability is classified under CWE-416, which denotes Use After Free errors. The exploitation vector involves a remote attacker crafting a specific HTML page containing JavaScript and DOM elements designed to trigger the race condition or logic error within the layout engine. By carefully controlling the timing of object creation and destruction, an attacker can manipulate memory contents such that when the stale pointer is dereferenced during layout calculation, it points to controlled data rather than freed memory. This allows for arbitrary read and write operations within the browser process context, which serves as the foundation for more severe exploits including code execution.
The operational impact of this vulnerability is significant because Google Chrome employs a multi-process architecture with strict sandboxing to limit the damage caused by compromised web content. The renderer processes are isolated from the operating system kernel and other sensitive components through restricted permissions. However, use-after-free vulnerabilities in core rendering modules like Layout often provide the necessary primitives for attackers to escape this sandbox environment. By achieving arbitrary code execution within the renderer process, an attacker can potentially exploit additional flaws or leverage browser-specific features to break out of the sandbox, thereby gaining control over the user's system with the privileges of the current user account. This aligns with ATT&CK technique T1059, Command and Scripting Interpreter, as well as techniques related to privilege escalation such as T1068 Exploitation for Privilege Escalation if the sandbox escape is successful.
Mitigation strategies primarily involve updating Google Chrome to version 157.0.8103.38 or later, where these memory safety issues have been addressed through rigorous code reviews and automated fuzzing efforts inherent in Chromium's development process. For organizations managing large fleets of endpoints, implementing centralized browser update policies is essential to ensure timely patch deployment. Additionally, security teams should monitor for indicators of compromise associated with drive-by download attacks that target known vulnerabilities in web browsers. While user education regarding suspicious links remains relevant, the technical fix relies on closing the memory management gap within the rendering engine itself. Developers and maintainers can further reduce risk by enabling compiler-based protections such as AddressSanitizer during development phases to detect these issues early before they reach production builds.