CVE-2026-95344 in Chrome
Summary
by MITRE • 09/29/2026
Race condition in DevTools in Google Chrome prior to 154.0.8037.57 allowed a remote attacker leveraging social engineering to bypass site isolation via a crafted Chrome extension. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 09/29/2026
The vulnerability identified as a race condition within the Developer Tools component of Google Chrome prior to version 154.0.8037.57 represents a significant breach in browser sandboxing mechanisms, specifically targeting site isolation protocols. Site isolation is a critical security feature designed to prevent cross-site scripting and data theft by ensuring that each website runs in its own process with distinct memory spaces. This architectural separation prevents malicious scripts from one origin from accessing sensitive data belonging to another origin. The flaw arises from a timing discrepancy during the initialization or state management of Chrome extensions, particularly those interacting with DevTools interfaces. When an attacker leverages social engineering techniques to persuade a user to install a crafted extension, they can exploit this race condition to manipulate internal states before security checks are fully enforced. This allows the malicious extension to bypass site isolation boundaries, effectively granting it access to data and resources that should remain isolated from other web contexts.
From a technical perspective, race conditions occur when software behavior depends on the relative timing of events, such as thread scheduling or message ordering. In this context, the vulnerability likely stems from insufficient synchronization mechanisms within the DevTools extension API handlers. An attacker can craft an extension that triggers specific asynchronous operations in rapid succession, creating a window where security policies are not yet applied or are incorrectly evaluated. This allows the extension to perform actions outside its designated scope, such as accessing cookies, local storage, or DOM elements from other origins. The severity is classified as medium by Chromium because while it requires user interaction and social engineering to initiate, successful exploitation leads to a fundamental compromise of browser isolation guarantees. This undermines one of the primary defenses against cross-site attacks in modern web browsers.
The operational impact of this vulnerability extends beyond simple data leakage. By bypassing site isolation, an attacker can potentially conduct sophisticated phishing campaigns that appear more legitimate by injecting content from trusted sites into malicious pages without triggering security warnings. Furthermore, access to isolated contexts enables attackers to steal session tokens, authentication credentials, and sensitive user information stored in browser memory. This capability significantly lowers the barrier for advanced persistent threats seeking long-term access or financial gain through credential theft. The reliance on social engineering means that while automated exploitation is difficult, targeted attacks against high-value individuals can be highly effective given the trust users place in installed extensions.
Mitigation strategies primarily involve immediate software updates to ensure all instances of Google Chrome are upgraded to version 154.0.8037.57 or later, where these synchronization issues have been resolved through improved state management and stricter validation checks within DevTools APIs. Organizations should enforce strict extension policies using enterprise management tools to prevent the installation of unverified or unnecessary extensions. User education remains critical; administrators must train employees to recognize social engineering attempts and verify the source and permissions requested by any Chrome extension before installation. Regular audits of installed extensions can help identify potentially malicious add-ons that may have been introduced through compromised websites or deceptive prompts.
This vulnerability aligns with Common Weakness Enumeration (CWE) category CWE-362, which describes concurrent execution race conditions where shared resources are accessed without proper synchronization. It also relates to CWE-841, specifically improper enforcement of a behavioral constraint during state transitions. In terms of the MITRE ATT&CK framework, this exploit maps to T1059 Command and Scripting Interpreter for executing malicious code within the browser environment and potentially T1203 Exploitation for Client Execution if combined with other vectors. The bypass of site isolation falls under techniques that aim to evade detection by breaking down trust boundaries established by security architectures. Understanding these mappings helps in developing more robust monitoring rules and intrusion detection signatures tailored to detect anomalous extension behaviors or unexpected cross-origin data access patterns within enterprise environments.