CVE-2026-87657 in Chrome
Summary
by MITRE • 09/09/2026
Use after free in V8 in Google Chrome prior to 153.0.8010.36 allowed a remote attacker who had compromised the renderer process to read memory inside the sandbox via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability identified as a use-after-free flaw within the V8 JavaScript engine, which powers Google Chrome prior to version 153.0.8010.36, represents a critical memory safety issue that undermines the browser's sandboxing mechanisms. This specific class of error occurs when a program continues to use a pointer after it has been freed from memory, leading to undefined behavior that can be exploited by malicious actors. In this context, an attacker who had already achieved code execution within the renderer process could leverage this flaw to access sensitive data residing in other sandboxed processes or system memory spaces. The severity of this vulnerability is classified as medium by Chromium security standards, reflecting its potential for privilege escalation and information disclosure despite requiring initial compromise of a less privileged environment.
From a technical perspective, V8 manages object lifecycles through garbage collection mechanisms that automatically reclaim memory occupied by objects no longer referenced in the application logic. However, if references to these objects are not properly invalidated or cleared before deallocation, dangling pointers may persist within the execution context. When the renderer process executes crafted HTML content containing malicious JavaScript, it can trigger a sequence of operations where an object is freed while still being accessed via stale references. This allows the attacker to read memory contents that should be isolated from the current execution scope, effectively bypassing the intended boundaries between different security zones within the browser architecture.
The operational impact of this vulnerability extends beyond simple data leakage, as it facilitates lateral movement and deeper system compromise. By reading memory inside the sandbox, an attacker can extract sensitive information such as session cookies, authentication tokens, or cryptographic keys stored in other tabs or processes. This capability significantly lowers the barrier for further exploitation, potentially leading to full control over the user's browsing environment or even host-level access if combined with additional vulnerabilities. The ability to read arbitrary memory locations also aids in defeating security mitigations like Address Space Layout Randomization by allowing attackers to locate critical structures and functions within the process address space.
This vulnerability aligns closely with Common Weakness Enumeration identifier CWE-416, which describes use after free conditions resulting from improper management of dynamic memory allocation. Furthermore, it maps to MITRE ATT&CK technique T1059, specifically command execution via scripting interpreters like JavaScript, and potentially T1078 for valid accounts if the renderer compromise stems from phishing or drive-by downloads. The exploitation path typically involves crafting a malicious webpage that triggers the race condition between object deallocation and reference retention within V8's internal data structures.
Mitigation strategies primarily involve upgrading to Google Chrome version 153.0.8010.36 or later, where these memory management issues have been addressed through rigorous code reviews and automated fuzzing efforts. Developers should ensure that all references to objects are explicitly nullified before freeing associated memory blocks to prevent dangling pointers from persisting in the execution context. Additionally, enabling strict sandbox policies and keeping browser plugins updated reduces the attack surface available for initial renderer compromise. Regular security audits focusing on JavaScript engine internals and adherence to secure coding practices regarding dynamic memory management are essential for preventing similar vulnerabilities in future releases.