CVE-2026-79264 in Chrome
Summary
by MITRE • 08/26/2026
Incorrect reference resolution in Preload in Google Chrome prior to 152.0.7977.65 allowed a remote attacker to bypass web origin policy 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 incorrect reference resolution within the preload mechanism of Google Chrome represents a significant deviation from expected browser behavior regarding resource loading and context isolation. Preload directives are designed to instruct user agents to fetch resources that will be required for navigation or rendering, thereby improving performance by initiating these requests early in the page load process. However, when this mechanism fails to resolve references correctly, it can lead to situations where a script loaded via preload is executed with privileges or context attributes that differ from those intended by the developer or expected under standard web security models. This flaw specifically impacts the integrity of the same-origin policy, which serves as the cornerstone of modern web application security by restricting how documents or scripts loaded from one origin can interact with resources from another origin.
In a typical scenario involving this vulnerability, an attacker constructs a malicious HTML page that leverages specific preload configurations to trick the browser into loading and executing code in a context where it should not have access. By manipulating the reference resolution logic, the attacker causes the browser to treat content originating from a different domain as if it were part of the current origin or grants it elevated permissions inadvertently. This bypass allows the malicious script to read sensitive data such as cookies, local storage contents, or DOM elements belonging to other origins that are normally protected by cross-origin restrictions. The severity is classified as medium because while the impact can be severe depending on the target site's sensitivity, successful exploitation requires specific conditions and often relies on social engineering or a compromised third-party resource to set up the initial crafted page.
The operational impact of this vulnerability extends beyond simple data theft. It undermines the trust model that web applications rely upon for secure communication between client-side scripts and servers. If an attacker can bypass origin policies, they may be able to perform cross-site request forgery attacks with greater ease, steal session tokens, or exfiltrate user-specific information without detection by standard security controls like Content Security Policy headers in certain configurations. This type of flaw is particularly dangerous because it exploits the browser's own optimization features against itself, making it difficult for users and even some automated security scanners to detect malicious activity based on traditional network traffic analysis alone.
From a classification perspective, this issue aligns with CWE-20 Improper Input Validation, as the browser failed to properly validate or resolve the references provided in the preload directives before executing them. It also relates closely to CWE-942 Cross-Site Scripting via Preload mechanisms and touches upon ATT&CK technique T1537 Domain Fronting if used to mask the true origin of the request, although primarily it is a violation of same-origin policy enforcement akin to CVEs involving cross-origin data leakage. The vulnerability highlights the complexity inherent in modern browser engines where performance optimizations like preloading must be carefully balanced with strict security boundaries to prevent privilege escalation or context confusion.
Mitigation for this issue involves ensuring that all instances of Google Chrome are updated to version 152.0.7977.65 or later, which contains the necessary patches to correct the reference resolution logic within the preload subsystem. For organizations managing large fleets of devices, deploying these updates through centralized endpoint management systems is critical to minimize exposure windows. Additionally, developers should adhere to strict Content Security Policy implementations that restrict unsafe inline scripts and validate resource origins rigorously. While client-side mitigations are essential, users must remain vigilant against phishing attempts or malicious websites that might attempt to exploit this flaw by hosting crafted HTML pages designed to trigger the incorrect resolution behavior in older browser versions.