CVE-2026-17909 in Chrome
Summary
by MITRE • 07/30/2026
Insufficient validation of untrusted input in Isolated Web Apps in Google Chrome prior to 151.0.7922.72 allowed a remote attacker to leak cross-origin data via malicious network traffic. (Chromium security severity: Low)
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Analysis
by VulDB Data Team • 07/30/2026
This vulnerability represents a critical weakness in Google Chrome's isolation mechanisms for web applications, specifically affecting versions prior to 151.0.7922.72. The flaw resides in the insufficient validation of untrusted input within isolated web apps, creating a pathway for cross-origin data leakage through malicious network traffic. The vulnerability stems from inadequate sanitization and validation processes that should normally separate different origin contexts within Chrome's security architecture. When untrusted input is processed without proper validation, it can potentially bypass isolation boundaries that are designed to prevent unauthorized access between different web origins.
The technical implementation of this vulnerability allows remote attackers to exploit the weak input validation by crafting malicious network traffic that manipulates the isolated web app environment. This creates a scenario where data from one origin can be accessed or leaked to another origin, effectively breaking the security boundary that should exist between different web applications. The attack vector specifically targets the network traffic processing within isolated contexts, leveraging the lack of proper input sanitization to extract sensitive information across origin boundaries.
From an operational impact perspective, this vulnerability poses significant risks to user privacy and data confidentiality, particularly in environments where multiple origins are accessed simultaneously through the same browser instance. The low severity classification by Chromium does not diminish the potential damage, as cross-origin data leakage can expose sensitive user information including session tokens, personal data, or other confidential content. This type of vulnerability directly violates fundamental web security principles and can enable more sophisticated attacks such as session hijacking or data exfiltration.
The vulnerability aligns with CWE-20, which addresses "Improper Input Validation," and relates to ATT&CK technique T1566 for phishing and T1071 for application layer protocol usage. Organizations should implement immediate mitigation strategies including updating to Chrome version 151.0.7922.72 or later, implementing network monitoring to detect anomalous traffic patterns, and reviewing isolation policies for web applications. Additionally, security teams should consider deploying web application firewalls and content security policies to add additional layers of protection against similar input validation attacks that could compromise isolated environments.