CVE-2026-85045 in Chrome
Summary
by MITRE • 09/03/2026
Race condition in V8 in Google Chrome prior to 152.0.7977.82 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 • 09/05/2026
The vulnerability identified as a race condition within the V8 JavaScript engine of Google Chrome prior to version 152.0.7977.82 represents a critical failure in memory synchronization mechanisms that can lead to arbitrary code execution. This flaw is classified under CWE-362, which describes concurrent access resulting in unexpected behavior due to improper locking or timing dependencies. In the context of modern web browsers, V8 serves as the core engine responsible for parsing and executing JavaScript code within a highly restricted sandbox environment designed to isolate untrusted content from the host operating system. The race condition likely arises during the handling of complex object states or memory allocation processes where multiple threads may interact with shared resources without adequate synchronization primitives such as mutexes or atomic operations. This temporal discrepancy allows an attacker to manipulate the state of objects in a way that bypasses standard type safety checks, leading to heap corruption or use-after-free scenarios that are difficult for static analysis tools to detect during normal operation.
From a technical perspective, race conditions in V8 often exploit the gap between checking an object's validity and using it later in execution flow, commonly known as Time-of-Check to Time-of-Use vulnerabilities. When a crafted HTML page triggers specific JavaScript operations involving rapid memory allocation or garbage collection cycles, the attacker can force the engine into a state where references become invalid while still being accessible through other pointers retained by the runtime. This inconsistency enables the manipulation of internal data structures such as hidden classes or property maps, which are fundamental to V8's optimization strategies like inline caching and polymorphic inlining. By carefully crafting the timing of these operations, an attacker can achieve arbitrary read-write access to memory regions outside the intended sandbox boundaries. The severity is rated high because successful exploitation does not require user interaction beyond visiting a malicious webpage, making it suitable for drive-by download attacks where no additional clicks or permissions are needed from the victim.
The operational impact of this vulnerability extends far beyond simple data leakage, as it facilitates full remote code execution within the browser's sandboxed context. While modern browsers employ multiple layers of defense including DEP, ASLR, and site isolation, a successful race condition exploit can often bypass these protections by achieving arbitrary memory writes that allow for ROP chain construction or direct shellcode injection into executable memory pages. This effectively breaks out of the V8 isolate environment, potentially leading to further privilege escalation depending on the browser's process architecture and sandboxing policies. The ATT&CK framework categorizes this type of exploitation under T1203, which covers Exploitation for Client Execution, highlighting how attackers leverage software vulnerabilities in client-side applications to establish a foothold within an organization's network perimeter. Once code execution is achieved inside the browser sandbox, subsequent techniques such as process injection or token manipulation may be employed to escape the sandbox entirely and gain control over the underlying operating system.
Mitigation strategies for this vulnerability primarily involve immediate patching of all affected Chrome installations to version 152.0.7977.82 or later, where Google has implemented fixes that enforce stricter synchronization protocols within V8's memory management subsystems. Organizations should ensure their endpoint detection and response systems are updated with signatures capable of detecting the specific heap spray patterns or shellcode indicators associated with this exploit chain. Additionally, enforcing strict Content Security Policy headers can help mitigate the impact by restricting the sources from which scripts can be loaded, thereby reducing the attack surface for drive-by exploitation attempts. For high-security environments, enabling sandboxing features such as Site Isolation and disabling JavaScript execution in untrusted contexts provide additional layers of defense that limit the effectiveness of memory corruption exploits even if a vulnerability is present. Regular security audits focusing on third-party libraries integrated into web applications can also help identify similar race conditions before they are exposed to end users.