CVE-2026-78934 in Chrome
Summary
by MITRE • 08/26/2026
Race condition in ReadAloud in Google Chrome prior to 152.0.7977.65 allowed a remote attacker leveraging social engineering 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 • 08/26/2026
The vulnerability identified as CVE-2024-8389 represents a critical race condition within the ReadAloud feature of Google Chrome, specifically affecting versions prior to 152.0.7977.65. This flaw resides in the browser's handling of asynchronous operations related to text-to-speech processing and DOM manipulation. Race conditions occur when software performs an operation out of sequence or at an unexpected time, often due to improper synchronization between concurrent threads or processes. In this context, the vulnerability arises from a timing window where the state of web page elements is modified while they are being accessed by the ReadAloud engine. An attacker can exploit this discrepancy by crafting a malicious HTML page that triggers specific JavaScript events and DOM changes simultaneously with calls to the speech synthesis API. The lack of proper locking mechanisms or atomic operations allows an adversary to manipulate the internal state before it is validated, leading to unexpected behavior within the browser's execution environment.
From a technical perspective, this race condition enables arbitrary code execution inside the Chrome sandbox, which is a significant security escalation. Modern browsers employ sandboxing techniques to isolate web content from the underlying operating system and user data. By exploiting the timing flaw in ReadAloud, an attacker can bypass these isolation boundaries. The crafted HTML page leverages social engineering tactics to persuade users into visiting the malicious site or interacting with embedded elements that trigger the exploit chain. Once triggered, the race condition allows for memory corruption or logic errors that result in the execution of arbitrary code within the restricted sandbox environment. Although the sandbox provides a layer of protection, successful exploitation can lead to further privilege escalation attacks depending on the specific browser version and configuration, potentially compromising user data or allowing lateral movement within a network if other vulnerabilities are present.
The operational impact of this vulnerability is severe due to its remote nature and reliance on social engineering. Because it requires user interaction such as visiting a malicious website, it falls under attack vectors that target human behavior rather than purely automated system flaws. The Chromium security severity rating of High reflects the potential for code execution and the relative ease with which an attacker can construct a proof-of-concept exploit using standard web technologies like HTML and JavaScript. This type of vulnerability is particularly dangerous because it does not require user credentials or prior access to the target machine, making it suitable for widespread phishing campaigns or drive-by download attacks where users are tricked into loading malicious content through deceptive links or advertisements.
To mitigate this risk, organizations must ensure that all instances of Google Chrome are updated to version 152.0.7977.65 or later immediately upon availability. Patch management processes should be prioritized for browsers due to their frequent exposure to web-based threats. Additionally, implementing strict content security policies can help restrict the execution of unauthorized scripts and reduce the attack surface available to attackers attempting to exploit race conditions in browser features. User awareness training is also critical; employees should be educated on recognizing suspicious links and avoiding interaction with untrusted web pages that request unusual permissions or exhibit abnormal behavior. Monitoring for anomalous network traffic originating from browsers can provide early detection of exploitation attempts, although the primary defense remains timely patching to close the race condition window in the ReadAloud component.
This vulnerability aligns with CWE-362, which describes concurrent execution access with unexpected interaction, a common class of flaws that lead to unpredictable software behavior and potential security breaches. Furthermore, it relates to MITRE ATT&CK technique T1059, specifically command scripting interpretation, as the exploit involves executing arbitrary code via JavaScript within the browser environment. Understanding these classifications helps in mapping defensive controls more effectively against similar future threats targeting web browsers and their embedded features.