CVE-2026-76020 in Chrome
Summary
by MITRE • 08/21/2026
Race condition in V8 in Google Chrome prior to 151.0.7922.173 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 • 08/24/2026
The vulnerability identified as a race condition within the V8 JavaScript engine, which powers Google Chrome prior to version 151.0.7922.173, represents a critical flaw in memory management and synchronization mechanisms during script execution. Race conditions occur when software behavior depends on the relative timing of uncontrollable events, such as thread scheduling or interrupt handling. In this specific instance, the V8 engine failed to properly synchronize access to certain internal data structures while processing complex JavaScript operations triggered by a crafted HTML page. This lack of atomicity allows an attacker to manipulate the state of memory in ways that bypass intended security constraints, leading to undefined behavior within the browser's execution environment.
From a technical perspective, this flaw falls under the category of CWE-362, which defines concurrent execution error or race condition vulnerabilities. The exploitation vector involves a remote attacker hosting a malicious webpage containing specially crafted JavaScript code designed to trigger the timing window where V8 incorrectly handles memory allocation or object state transitions. By carefully crafting the payload, an attacker can cause the engine to access freed memory or write to invalid addresses before proper checks are completed. This specific type of vulnerability is particularly dangerous because it often leads to heap corruption, which serves as a foundational primitive for more severe exploits such as arbitrary code execution or privilege escalation within the browser sandbox.
The operational impact of this vulnerability is significant due to its potential for remote code execution with high severity ratings assigned by Chromium security teams. A successful exploit allows an attacker to execute arbitrary commands inside the Chrome sandbox, effectively breaking out of the restricted environment that isolates web content from the underlying operating system. While modern browsers employ multiple layers of defense such as ASLR and DEP, a race condition in V8 can potentially bypass these protections if it leads to specific memory corruption patterns like use-after-free or type confusion. This enables the attacker to gain control over the browser process, which can then be leveraged to access sensitive user data, install malware, or pivot into other systems on the network depending on the context of the browsing session.
In terms of threat modeling and attack classification, this vulnerability aligns with MITRE ATT&CK techniques related to initial code execution via web-based attacks. Specifically, it relates to T1059, Command and Scripting Interpreter, where JavaScript is used as a vehicle for delivering malicious payloads. The exploitation relies on social engineering or drive-by download tactics where the victim visits a compromised or attacker-controlled website. Once executed, the payload can establish persistence, exfiltrate credentials, or perform further reconnaissance within the context of the user's browser profile.
Mitigation strategies primarily involve immediate patching to version 151.0.7922.173 or later, which includes fixes for the synchronization logic in V8. Organizations should ensure that endpoint protection solutions are updated to detect known exploit patterns associated with this vulnerability. Additionally, users can reduce risk by enabling site isolation features within Chrome and avoiding interaction with untrusted web content until updates are applied. Security teams should monitor network traffic for indicators of compromise related to JavaScript-based exploits and review browser usage policies to minimize exposure to potentially malicious websites during the remediation window.