CVE-2026-121119 in Chrome
Summary
by MITRE • 11/03/2026
Use after free in Controls 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)
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Analysis
by VulDB Data Team • 11/04/2026
The vulnerability identified as a use-after-free condition within the Controls component of Google Chrome prior to version 157.0.8103.38 represents a critical memory management error that compromises the integrity of the browser's execution environment. This specific flaw arises when the application continues to reference a pointer after the memory it points to has been deallocated or freed by another part of the system. In the context of web browsers, such errors are particularly dangerous because they can be triggered through standard web content rendering processes. An attacker who crafts a malicious HTML page containing specially designed scripts and DOM manipulations can exploit this timing discrepancy. When the browser attempts to access the Controls component using the stale pointer, it interacts with memory that may have been reallocated for different purposes or is no longer valid, leading to undefined behavior within the process space.
The operational impact of this vulnerability is severe due to its potential for remote code execution inside the sandboxed environment where Chrome typically isolates web content from the host operating system. By carefully crafting the exploit payload, an attacker can manipulate the heap layout and control the data written into the freed memory region. This manipulation allows for arbitrary read or write operations, which can be leveraged to bypass security mitigations such as stack canaries, address space layout randomization, and full RELRO protections. Once these defenses are circumvented through precise memory corruption techniques like heap spraying or type confusion attacks derived from the use-after-free state, the attacker gains the ability to execute arbitrary code with the privileges of the browser process. This effectively breaks out of the intended isolation boundaries if further exploitation steps target lower-level components or escape mechanisms exist within the sandbox implementation itself.
From a classification perspective, this vulnerability aligns closely with CWE-416, which defines use after free as referencing memory that has already been freed. The attack vector is categorized under ATT&CK technique T1203, specifically focusing on exploitation for client-side code execution via browser vulnerabilities. The severity rating of High by the Chromium security team reflects the ease with which such flaws can be weaponized in modern web environments and their direct consequence on user system compromise. Unlike remote code execution vulnerabilities that require complex multi-stage exploits, use-after-free bugs often provide a reliable primitive for achieving arbitrary memory access, making them a primary target for exploit developers aiming to achieve persistent or immediate control over the victim's machine through malicious websites.
Mitigation strategies primarily involve updating Google Chrome to version 157.0.8103.38 or later, where these memory management issues have been addressed by ensuring that pointers are properly nullified after deallocation and that access checks are enforced before any operation on potentially freed objects. For organizations managing large fleets of endpoints, implementing automated patching solutions is essential to reduce the window of exposure. Additionally, deploying browser hardening policies such as restricting script execution in untrusted zones or utilizing sandboxed iframes can provide an additional layer of defense against exploitation attempts. Security teams should also monitor for indicators of compromise related to unusual memory allocation patterns or unexpected process behavior that might indicate active exploitation of this vulnerability before patches are fully deployed across the infrastructure.