CVE-2026-79251 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 to potentially bypass web origin policy via a crafted HTML page. (Chromium security severity: Medium)
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 08/26/2026
The vulnerability identified as an improper input validation flaw within the network stack of Google Chrome prior to version 152.0.7977.65 represents a significant deviation from expected secure coding practices regarding how user-supplied data is processed before being utilized in critical security contexts. This specific defect allows for the potential bypassing of web origin policies, which are fundamental mechanisms designed to isolate content loaded from different sources to prevent malicious scripts on one page from obtaining access to sensitive data on another page with a different origin. The root cause lies in the insufficient sanitization or validation of input parameters passed through the network layer, where the browser fails to correctly enforce boundaries between distinct security contexts. This oversight creates an avenue for remote attackers to craft specific HTML pages that exploit this logic error, effectively tricking the browser into treating content from a malicious origin as if it originated from a trusted source.
From a technical perspective, web origin policies rely on strict checks of scheme, host, and port combinations to determine whether two resources share the same security context. When input validation is improper within the network module, these checks may be circumvented through carefully constructed payloads that manipulate how the browser interprets the request headers or URL structures. By exploiting this flaw, an attacker can execute cross-origin requests that would normally be blocked by the Same-Origin Policy. This capability undermines the isolation guarantees provided by modern web browsers, allowing malicious scripts to read sensitive data such as cookies, local storage contents, or DOM elements from other domains without authorization. The severity of this issue is classified as medium within the Chromium security framework because while it does not typically allow for direct arbitrary code execution on the host system, it significantly weakens the sandboxing model that protects users against drive-by attacks and data theft scenarios prevalent in today's web ecosystem.
The operational impact of this vulnerability extends beyond simple data leakage to include potential session hijacking and credential theft if combined with other attack vectors such as Cross-Site Scripting or phishing campaigns. An attacker leveraging this flaw could potentially access private information stored by web applications, manipulate user interactions across different sites, or perform actions on behalf of the victim without their consent. This erosion of trust in browser security mechanisms can lead to broader compromises where attackers gain persistent footholds within a user's digital environment. The ability to bypass origin policies is particularly dangerous because it targets the core assumption that browsers provide strong isolation between web pages, making this vulnerability a high-value target for sophisticated threat actors aiming to exfiltrate sensitive corporate or personal data from protected environments.
To mitigate the risks associated with this vulnerability, organizations and individual users must ensure that Google Chrome is updated to version 152.0.7977.65 or later as soon as possible. Automatic update mechanisms should be verified to be active to prevent exposure during the window between patch release and deployment. For enterprise environments, it is advisable to implement strict Content Security Policy headers on web applications served by internal systems to add an additional layer of defense-in-depth against origin bypass attempts. Additionally, security teams should monitor for unusual network traffic patterns that might indicate exploitation attempts, such as unexpected cross-origin requests or anomalous data exfiltration activities. Regular vulnerability assessments and penetration testing focused on browser-based attack surfaces can help identify similar implementation flaws before they are exploited in the wild.
This incident aligns with common weakness enumerations related to input validation failures and access control issues. Specifically, it relates to CWE-20 Improper Input Validation, where insufficient checking of user inputs leads to security vulnerabilities, and CWE-942 Cross-Site Request Forgery or data leakage scenarios enabled by broken origin checks. In the context of the MITRE ATT&CK framework, this vulnerability facilitates techniques associated with Collection via Browser Hijacking or Data from Information Repositories, as it allows attackers to access stored credentials and sensitive documents through compromised browser sessions. Understanding these mappings helps security professionals prioritize remediation efforts based on established industry standards for classifying and responding to web application vulnerabilities.