CVE-2026-87564 in Chrome
Summary
by MITRE • 09/09/2026
Type confusion in V8 in Google Chrome prior to 153.0.8010.36 allowed a remote attacker to read memory inside the sandbox via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability identified as a type confusion issue within the V8 JavaScript engine, which powers Google Chrome prior to version 153.0.8010.36, represents a critical failure in runtime memory safety checks. Type confusions occur when an application incorrectly interprets the data type of a variable or object during execution, leading to operations being performed on data structures that do not match their expected format. In this specific instance, the flaw resides within V8's handling of JavaScript objects and arrays, where the engine failed to properly validate the internal structure types before performing memory access operations. This oversight allowed for an inconsistency between how the garbage collector managed object layouts and how the JIT compiler generated machine code to access those same structures, creating a window for exploitation that bypassed standard sandbox protections.
From a technical perspective, this vulnerability is classified under CWE-843, which denotes Access of Resource Using Incompatible Type Constraints. The core mechanism involves an attacker crafting a malicious HTML page containing specific JavaScript payloads designed to trigger the type confusion state within V8. By carefully manipulating object shapes and array types during execution, the attacker can force the engine to treat a pointer as a different data type than intended. This misinterpretation allows for arbitrary read operations on memory locations that are typically isolated from user-space code by Chrome's multi-process architecture. The ability to perform these reads is significant because it breaks the isolation boundary between untrusted web content and privileged browser processes, effectively neutralizing one of the primary defense-in-depth layers employed by modern browsers.
The operational impact of this vulnerability is severe due to its potential for remote exploitation via a simple webpage visit or through malicious advertising scripts embedded in legitimate sites. A remote attacker does not require user interaction beyond visiting the crafted page, making it suitable for drive-by download attacks. The primary consequence here is unauthorized memory disclosure rather than immediate code execution, although such information leaks are often used as stepping stones to achieve arbitrary read/write primitives and ultimately full sandbox escape. This aligns with MITRE ATT&CK technique T1057, which covers Process Discovery through Memory Access, but in this context, it serves the broader goal of Information Exfiltration (T1005). The high severity rating assigned by Chromium reflects the ease with which an attacker can leverage this flaw to gain insights into browser internals, potentially leading to further exploitation chains that compromise system integrity.
Mitigation for this vulnerability primarily involves updating Google Chrome and its underlying V8 engine to version 153.0.8010.36 or later, where the type checking logic has been hardened to prevent incompatible memory access patterns. For organizations managing large fleets of devices, ensuring automatic update policies are enforced is critical to closing this window of exposure. Additionally, security teams should monitor for indicators of compromise related to V8 exploitation techniques and consider deploying browser isolation solutions or advanced endpoint detection systems that can identify anomalous memory access behaviors indicative of type confusion exploits. While user education remains a secondary defense against visiting malicious sites, technical controls such as content security policies and sandboxing enhancements provide the most effective protection against this class of vulnerabilities until patches are applied.