CVE-2026-106201 in Chrome
Summary
by MITRE • 10/06/2026
Race condition in V8 in Google Chrome prior to 155.0.8059.39 allowed a remote attacker to execute arbitrary code inside the sandbox via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability identified as a race condition within the V8 JavaScript engine, which powers Google Chrome prior to version 155.0.8059.39, represents a significant threat to application-level isolation and memory safety. This flaw arises from improper synchronization mechanisms during concurrent operations involving object state transitions or garbage collection processes. In complex web applications that rely heavily on asynchronous JavaScript execution, the V8 engine manages multiple threads of control to optimize performance. However, when specific race conditions occur, it becomes possible for an attacker to manipulate the timing of these operations such that internal data structures are accessed in an inconsistent or partially updated state. This inconsistency allows for memory corruption vulnerabilities, specifically type confusion or use-after-free scenarios, which serve as the foundational exploit primitives necessary for arbitrary code execution.
From a technical perspective, this vulnerability falls under the category of CWE-362, Concurrent Execution using Shared Resource with Improper Synchronization. The core issue lies in the failure to properly lock shared resources during critical sections of memory management or object property access within the V8 runtime environment. When an attacker crafts a malicious HTML page containing specially designed JavaScript code, they can trigger these race conditions by exploiting the non-deterministic nature of thread scheduling and garbage collection cycles. By carefully crafting payloads that force specific timing windows, the attacker can cause the engine to misinterpret memory layouts or access freed memory regions as valid objects. This leads to a breach in the sandbox boundary, allowing code executed within the browser context to escape into higher-privilege system spaces or execute arbitrary instructions outside the intended security constraints of the web page.
The operational impact of this vulnerability is severe due to its potential for remote code execution without user interaction beyond visiting a malicious website. Attackers can leverage this flaw through drive-by download techniques, where simply loading a compromised webpage triggers the exploit chain. Once the sandbox escape is achieved, the attacker gains the ability to execute arbitrary code with the privileges of the current user process. This can lead to full system compromise, data exfiltration, installation of persistent malware, or lateral movement within a network if the browser is used as an entry point for further attacks. The medium severity rating assigned by Chromium reflects the complexity required to reliably exploit this race condition in real-world scenarios, yet it remains highly dangerous given the widespread use of Chrome and V8 across various platforms including desktop operating systems and mobile devices.
Mitigation strategies primarily involve updating to Google Chrome version 155.0.8059.39 or later, where these synchronization issues have been addressed through improved locking mechanisms and enhanced validation checks within the V8 engine. For organizations unable to immediately patch all endpoints, implementing strict content security policies can help mitigate some risks by restricting the execution of inline scripts and limiting access to potentially dangerous APIs. Additionally, deploying browser isolation solutions or sandboxing technologies at the network level can reduce the blast radius if a user inadvertently accesses malicious content. Security teams should also monitor for indicators of compromise associated with exploit kits that target known V8 vulnerabilities and ensure that endpoint detection and response systems are configured to detect unusual memory access patterns indicative of heap exploitation attempts.
This incident highlights the critical importance of rigorous concurrency control in high-performance JavaScript engines. It aligns with ATT&CK technique T1059, Command and Scripting Interpreter, specifically regarding how attackers use scripting languages like JavaScript to achieve initial execution before escalating privileges. The vulnerability underscores the ongoing challenge in maintaining memory safety guarantees in dynamically typed languages that rely on just-in-time compilation and aggressive optimization techniques. Continuous integration of formal verification methods for critical synchronization paths within engine codebases is recommended to prevent similar race conditions from being introduced during future development cycles.