CVE-2026-91744 in Chrome
Summary
by MITRE • 09/15/2026
Race condition in PlatformIntegration in Google Chrome on on Mac prior to 153.0.8010.47 allowed a remote attacker who had compromised the renderer process and leveraged social engineering to obtain sensitive information via a crafted HTML page. (Chromium security severity: High)
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Analysis
by VulDB Data Team • 09/15/2026
The vulnerability identified in Google Chrome on macOS prior to version 153.0.8010.47 represents a critical race condition within the PlatformIntegration component of the Chromium engine. This flaw arises from improper synchronization mechanisms when handling inter-process communication or state transitions involving platform-specific APIs. In modern browser architectures, particularly those based on Chromium, different processes such as renderers and utility services operate with varying levels of privilege to contain potential security breaches. The race condition occurs when multiple threads access shared resources without adequate locking or atomic operations, creating a window where the application's internal state can be manipulated before it is properly validated or updated. This specific timing flaw allows an attacker who has already gained control over a renderer process to exploit this gap in logic, effectively bypassing intended security boundaries that are supposed to isolate untrusted content from sensitive system resources.
The operational impact of this vulnerability is significant because it facilitates the escalation of privileges for an attacker operating within the sandboxed environment of a web page. Typically, renderer processes are heavily restricted and cannot directly access local file systems or sensitive user data due to strict sandboxing policies enforced by the browser's security model. However, through social engineering techniques such as phishing or malicious website hosting, an adversary can trick a victim into loading a crafted HTML page that triggers this race condition. By carefully timing requests against the PlatformIntegration component, the attacker can force the browser to perform actions with higher privileges than intended for the renderer process. This leads to unauthorized access to sensitive information stored on the local machine or accessible via platform APIs, compromising user privacy and potentially leading further system compromise depending on what data is exposed through this channel.
From a classification perspective, this vulnerability aligns closely with CWE-362, which describes concurrent execution race conditions where software performs multiple operations simultaneously without proper synchronization. The exploitation vector also maps to MITRE ATT&CK techniques related to privilege escalation and defense evasion, specifically how attackers leverage timing flaws in operating system or application logic to bypass security controls. The severity rating of High by the Chromium project reflects the potential for data exfiltration from a context that is normally considered secure against remote code execution attacks originating solely from web content. It underscores the complexity of maintaining strict isolation boundaries when interacting with native platform features, highlighting the ongoing challenge in browser development to prevent side-channel and timing-based exploits even within sandboxed environments.
Mitigation strategies primarily involve applying the latest security patches provided by Google for Chrome on macOS, which address these synchronization issues by implementing stricter locking mechanisms or atomic operations within the PlatformIntegration module. Beyond immediate patching, organizations should enforce strict content security policies (CSP) to limit the capabilities of scripts running in browser contexts and reduce the attack surface available to social engineering campaigns. Additionally, user education regarding phishing risks remains crucial since initial access often relies on deceptive practices rather than purely technical exploitation. Regular updates and monitoring for anomalous behavior from renderer processes can also help detect attempts to exploit such timing vulnerabilities before they result in significant data loss or system compromise.