CVE-2026-78899 in Chrome
Summary
by MITRE • 08/26/2026
Use after free in V8 in Google Chrome prior to 152.0.7977.65 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 • 08/26/2026
The vulnerability identified as a use-after-free error within the V8 JavaScript engine, which powers Google Chrome prior to version 152.0.7977.65, represents a critical memory management flaw that enables remote code execution under specific conditions. This type of defect occurs when a program continues to use a pointer after the memory it points to has been freed or reallocated. In the context of V8, this typically involves JavaScript objects being garbage collected while still referenced by other parts of the engine's internal structures or active scripts. When an attacker crafts a malicious HTML page that triggers this specific sequence of events, they can manipulate the state of the memory allocator such that the reused memory block contains data controlled by the attacker rather than valid application logic.
The operational impact of this vulnerability is severe due to its potential for arbitrary code execution within the browser's sandboxed environment. Modern browsers employ a multi-process architecture where each tab or site runs in a restricted context known as the renderer process, which operates under strict security boundaries designed to prevent access to the host operating system and user data. However, use-after-free vulnerabilities provide an exploit primitive that allows attackers to achieve arbitrary read and write capabilities within this sandboxed space. By carefully crafting heap layouts and exploiting race conditions or logic errors in memory management, a remote attacker can overwrite function pointers or virtual table entries, thereby redirecting the execution flow of the browser process to inject and execute shellcode. This effectively breaks out of the intended isolation boundaries if combined with additional exploitation techniques targeting other components like the GPU process or sandbox escape mechanisms.
From a classification perspective, this flaw aligns directly with CWE-416, which defines use after free as referencing memory that has already been freed. The attack vector is classified under MITRE ATT&CK technique T1203, specifically focusing on exploitation for client-side execution via web browsers. The severity rating of High by the Chromium security team reflects the ease with which such vulnerabilities can be leveraged in drive-by download scenarios or malicious websites where users may inadvertently trigger the exploit upon visiting a compromised page. These attacks often require no user interaction beyond loading the webpage, making them particularly dangerous for general internet browsing activities.
Mitigation strategies primarily involve updating to Google Chrome version 152.0.7977.65 or later, which includes patches that correct the memory management logic within V8 to prevent dangling pointers from being dereferenced after deallocation. Security researchers and developers should also ensure that static analysis tools are configured to detect potential use-after-free patterns in JavaScript engine codebases. For end-users, enabling automatic updates for browsers is crucial to maintain protection against such high-severity vulnerabilities. Additionally, employing browser security features like site isolation can help limit the blast radius of any successful exploitation by further restricting cross-origin data access and reducing the effectiveness of heap spraying techniques often used in conjunction with use-after-free exploits.