CVE-2026-79065 in Chrome
Summary
by MITRE • 08/26/2026
Improper input validation in Network in Google Chrome prior to 152.0.7977.65 allowed a remote attacker who had compromised the renderer process 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 improper input validation flaw within Google Chrome prior to version 152.0.7977.65 represents a significant breach in the browser's isolation mechanisms, specifically targeting the network stack. This issue stems from insufficient sanitization or type-checking of data inputs processed by the networking components when handling requests initiated through web pages. In modern browsers like Chrome, security relies heavily on the principle of least privilege and strict process separation, where renderer processes are sandboxed to prevent them from accessing sensitive system resources directly. However, this flaw allowed a compromised renderer process to exploit weaknesses in how network-related inputs were validated before being passed up to higher-level browser components or executed by the main thread. The core technical failure lies in the assumption that data originating from web content is inherently safe for certain operations without rigorous verification of its structure and intent, leading to unexpected behavior when maliciously crafted HTML pages are processed.
From an operational perspective, this vulnerability enables a remote attacker who has already achieved code execution within a renderer process to bypass web origin policies. Web origin policy is a critical security mechanism that restricts how documents or scripts loaded from one origin can interact with resources from another origin. By exploiting the improper input validation in the network layer, the attacker could manipulate network requests to appear as if they originated from a trusted domain or access restricted APIs and data stores that should be inaccessible due to cross-origin restrictions. This effectively neutralizes one of the primary defenses against Cross-Site Scripting (XSS) attacks and other web-based exploits, allowing the malicious script to exfiltrate sensitive user data, such as cookies, session tokens, or personal information stored in local storage, from domains that would normally be isolated from the attacker's context.
The classification of this vulnerability under CWE-20 Improper Input Validation highlights the fundamental nature of the defect, where software fails to verify that input meets expected criteria before processing it. In the context of browser security architecture, this flaw aligns with MITRE ATT&CK techniques related to Defense Evasion and Credential Access, specifically those involving bypassing user interface restrictions or manipulating network connections for unauthorized data access. The severity is rated as Medium by Chromium because while it requires an initial compromise of a renderer process, which typically involves exploiting another vulnerability like XSS or a remote code execution flaw in web content, the ability to break origin policies significantly amplifies the impact of that initial foothold. It transforms a contained script injection into a broader data breach scenario where cross-domain boundaries are rendered ineffective.
Mitigation for this issue primarily relies on updating Google Chrome to version 152.0.7977.65 or later, which includes patches addressing the input validation logic within the network stack. For organizations deploying Chrome at scale, ensuring automatic updates are enabled is crucial to maintain protection against such vulnerabilities. Additionally, users and administrators should employ browser hardening techniques, such as disabling JavaScript in untrusted sites using extensions like NoScript, although this may impact usability. From a development standpoint, reinforcing input validation routines within the Chromium codebase involves implementing stricter type checking and ensuring that all network-related inputs are validated against allowlists of expected formats rather than relying on negative checks or assumptions about data integrity. Regular security audits and fuzzing tests targeting the browser's networking components can help identify similar flaws before they reach production releases, thereby maintaining the robustness of the sandbox environment.