CVE-2026-87618 in Chrome
Summary
by MITRE • 09/09/2026
Incorrect reference resolution in Storage in Google Chrome on on Windows prior to 153.0.8010.36 allowed a remote attacker who had compromised the renderer process to potentially execute arbitrary code outside the sandbox via a crafted HTML page. (Chromium security severity: Low)
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability identified in Google Chrome for Windows prior to version 153.0.8010.36 represents a critical failure in memory management and reference handling within the browser's storage subsystem. This flaw, classified as an incorrect reference resolution issue, stems from improper lifecycle management of objects involved in data persistence operations. When a renderer process interacts with the storage APIs to read or write persistent data such as cookies, local storage entries, or IndexedDB records, the underlying Chromium architecture must ensure that all pointers and handles remain valid throughout the operation. In this specific instance, the browser failed to correctly validate whether an object referenced by the renderer was still alive in memory before attempting to access it. This lapse creates a window of opportunity where stale or dangling references can be exploited, leading to undefined behavior within the privileged storage components that operate outside the strict confines of the standard renderer sandbox.
From a technical perspective, this vulnerability is categorized under CWE-416, which describes Use After Free conditions. The core mechanism involves a scenario where memory allocated for a specific storage-related object is freed or deallocated by one part of the system while another part retains a reference to that same memory block. When the renderer process executes a crafted HTML page designed to trigger this race condition or improper state transition, it can manipulate these dangling pointers. Because the storage subsystem often runs with higher privileges than the untrusted renderer processes, exploiting this flaw allows an attacker to bypass the sandbox isolation mechanisms. The Chromium security team has assessed the severity of this issue as Low due to the specific prerequisites required for exploitation, primarily that the attacker must already have code execution capabilities within a compromised renderer process.
The operational impact of this vulnerability is significant despite its low severity rating in terms of initial access requirements. If successfully exploited, an attacker who has managed to compromise a renderer process through other means can escalate their privileges by executing arbitrary code outside the sandbox. This effectively breaks the fundamental security model of modern web browsers, which relies on isolating untrusted web content from sensitive system resources and user data. By escaping the sandbox, the malicious actor gains direct access to the host operating system's kernel-level or high-privilege user-space components. This can lead to full system compromise, allowing for the installation of persistent malware, theft of sensitive credentials stored in browser profiles, or further lateral movement within a network environment if the compromised machine is part of an enterprise infrastructure.
Mitigation strategies primarily focus on timely patching and defense-in-depth measures. The most effective remediation is to update Google Chrome to version 153.0.8010.36 or later, where this reference resolution logic has been corrected to ensure proper validation of object lifecycles before access. Organizations should enforce automated browser updates across all endpoints to minimize the window of exposure. Additionally, security teams can implement application control policies such as Microsoft AppLocker or Windows Defender Application Control to restrict the execution of untrusted scripts and binaries within renderer processes. Network segmentation and strict Content Security Policy (CSP) configurations also help limit the attack surface by preventing malicious content from being loaded in the first place. Monitoring for unusual memory access patterns or privilege escalation attempts can provide early detection indicators, although proactive patching remains the primary defense against this class of vulnerabilities. This incident underscores the importance of rigorous code review practices within browser engines to prevent subtle logic errors that can lead to severe security breaches when combined with renderer compromise scenarios aligned with ATT&CK techniques related to process injection and sandbox escape.