CVE-2026-79252 in Chrome
Summary
by MITRE • 08/26/2026
Information leak in ServiceWorker in Google Chrome prior to 152.0.7977.65 allowed a remote attacker to obtain cross-origin data via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 08/26/2026
The vulnerability identified as an information leak within the Service Worker component of Google Chrome, specifically in versions prior to 152.0.7977.65, represents a significant breach of browser isolation principles. This flaw allows a remote attacker to bypass cross-origin restrictions by leveraging a crafted HTML page that interacts with maliciously constructed service workers. The core issue lies in the improper handling or exposure of data across different origins during the lifecycle management and message passing mechanisms inherent to Service Workers. By exploiting this weakness, an adversary can access sensitive information belonging to other web applications running within the same browser context, effectively violating the Same-Origin Policy which is fundamental to modern web security architecture.
From a technical perspective, Service Workers act as proxy servers that sit between web applications, the browser, and the network. They are designed to enable features such as offline experiences, push notifications, and background syncs while maintaining isolation from the main thread for performance and security reasons. However, in this specific instance, the implementation failed to correctly sanitize or restrict access to cross-origin resources when processing requests initiated by a service worker controlled by an attacker. This misconfiguration creates a pathway through which data intended for one origin can be intercepted or read by another unauthorized origin. The attack vector typically involves social engineering or drive-by download tactics where a victim visits a webpage containing the crafted HTML and associated malicious scripts that trigger the vulnerable code path within the browser engine.
The operational impact of this vulnerability is substantial, particularly in environments where users frequently interact with multiple web applications simultaneously. An attacker who successfully exploits this flaw can exfiltrate sensitive user data such as authentication tokens, personal identifiable information, or proprietary application state stored by legitimate websites. This compromise undermines user trust and can lead to further downstream attacks including account takeover, session hijacking, or corporate espionage if the accessed data contains confidential business intelligence. The severity is classified as medium because while it does not allow for arbitrary code execution on the host system, the potential for large-scale data theft across multiple domains poses a serious risk to privacy and security integrity.
This vulnerability aligns with CWE-200, which categorizes information exposure issues where an attacker gains access to sensitive information without authorization. Furthermore, in terms of offensive cyber operations mapping, this exploit technique corresponds to ATT&CK tactic T1530 Data from Local System combined with techniques for web application reconnaissance such as T1078 Valid Accounts if session cookies are stolen or T1114 Email Collection depending on the specific data targeted. The exploitation relies heavily on social engineering elements typical of T1566 Phishing to get users to load the malicious payload, followed by automated script execution that leverages the browser's native capabilities against itself.
Mitigation strategies primarily involve updating Google Chrome to version 152.0.7977.65 or later where these logic errors in Service Worker handling have been corrected and validated through rigorous security testing. For organizations unable to immediately patch all endpoints, implementing strict Content Security Policy directives can help mitigate the risk by restricting how scripts interact with external resources and limiting the scope of service worker registration origins. Additionally, educating users about the risks of visiting untrusted websites remains a critical defense layer since the initial access vector requires user interaction or navigation to a malicious site. Regular security audits focusing on web application isolation boundaries and continuous monitoring for anomalous data exfiltration patterns can further reduce the attack surface associated with such browser-level vulnerabilities.