CVE-2026-121127 in Chrome
Summary
by MITRE • 11/03/2026
Use after free in WebAudio 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)
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 11/04/2026
The vulnerability identified as a use-after-free condition within the WebAudio component of Google Chrome prior to version 157.0.8103.38 represents a critical memory management flaw that compromises the integrity and confidentiality of the browser environment. This specific defect arises when the application continues to reference a memory block after it has been freed, leading to undefined behavior that can be exploited by malicious actors. In the context of modern web browsers, such vulnerabilities are particularly dangerous because they reside within high-privilege components responsible for handling multimedia data, which often have broader access to system resources than standard JavaScript contexts. The presence of this flaw indicates a failure in proper reference counting or object lifecycle management within the WebAudio API implementation, allowing an attacker to manipulate pointers that point to deallocated memory regions.
From a technical perspective, use-after-free vulnerabilities are among the most prevalent and severe classes of software defects because they provide a reliable mechanism for achieving arbitrary code execution. When an attacker crafts a malicious HTML page containing specific JavaScript sequences designed to trigger this race condition or logical error, they can control the content that overwrites the freed memory block. By carefully crafting subsequent allocations, the attacker can place shellcode or other executable payloads into the reclaimed memory space. Upon dereferencing the stale pointer, the browser executes this injected code within the context of the WebAudio process. This exploitation path is significant because it bypasses many standard security mitigations that rely on preventing direct execution from data segments, as the exploit leverages legitimate program flow to jump to attacker-controlled addresses.
The operational impact of this vulnerability is severe due to its potential for remote code execution via a crafted web page. An adversary does not need physical access or prior authentication; they merely need to lure a victim into visiting a malicious website hosted on any server under their control. Once the user interacts with the page, potentially through automatic script execution or minimal interaction depending on browser settings and exploit complexity, the attacker gains the ability to execute arbitrary commands within the sandboxed environment of Chrome. While modern browsers employ robust sandboxing mechanisms such as site isolation and process separation, a successful use-after-free exploit can often lead to sandbox escape techniques that grant access to the underlying operating system. This effectively neutralizes the protective boundaries intended to contain web-based threats, allowing for full compromise of the user's machine including data theft, installation of persistent malware, or lateral movement within a network if connected.
This vulnerability aligns with Common Weakness Enumeration identifier CWE-416, which describes use after free errors where memory is accessed after it has been released back to the system. The exploitation technique maps directly to MITRE ATT&CK tactic T1203, specifically the subtechnique of exploitation for client execution, as well as techniques related to sandbox escape if the attacker leverages this initial foothold to break out of the browser's restricted environment. Industry standards emphasize that such memory corruption bugs are often the result of complex interactions between multiple objects or asynchronous operations where timing is critical, making them difficult to detect through static analysis alone without specialized fuzzing tools.
Mitigation strategies for this vulnerability primarily involve immediate patching by upgrading Google Chrome to version 157.0.8103.38 or later, which contains the necessary code fixes to properly manage memory allocation and deallocation within the WebAudio subsystem. Organizations should enforce automated update policies across all endpoints to ensure that users are protected against known exploits in real-time. Additionally, security teams can implement browser hardening measures such as disabling JavaScript execution for untrusted sites using content security policies or sandboxing profiles where feasible. Monitoring network traffic for connections to suspicious domains hosting crafted HTML pages and employing endpoint detection and response solutions capable of identifying anomalous process behavior associated with memory corruption exploits further reduces the attack surface. Regular vulnerability assessments and penetration testing focused on web application interactions can also help identify similar implementation flaws before they are exploited in the wild.