CVE-2026-87656 in Chrome
Summary
by MITRE • 09/09/2026
Improper state validation in Safebrowsing in Google Chrome prior to 153.0.8010.36 allowed a remote attacker to bypass system access restrictions via a crafted HTML page. (Chromium security severity: Low)
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability identified as an improper state validation flaw within the Safebrowsing component of Google Chrome prior to version 153.0.8010.36 represents a significant deviation from expected security boundaries in web browsing contexts. This issue stems from a logical error where the browser fails to correctly validate or enforce internal states during the processing of navigation requests and safety checks. Specifically, the Safebrowsing subsystem is responsible for evaluating URLs against known malicious databases to prevent users from accessing phishing sites, malware distribution points, and other harmful content. When this component does not properly verify its operational state before allowing a page load or script execution, it creates an opportunity for attackers to manipulate the flow of information processing within the browser engine.
From a technical perspective, the core flaw lies in the failure to maintain strict consistency between the security policy enforcement mechanisms and the actual rendering pipeline. An attacker can craft a specific HTML page that exploits this state inconsistency by triggering actions before the Safebrowsing checks are fully completed or by bypassing them entirely through race conditions or malformed request structures. This allows the browser to proceed with loading content that should have been blocked, effectively neutralizing one of Chrome's primary defense layers against web-based threats. The Chromium security team has classified this issue as low severity because while it represents a clear breach in logic, the practical exploitation requires specific user interaction and crafted payloads that may not be easily automated at scale compared to memory corruption vulnerabilities.
The operational impact of this vulnerability is primarily centered on the bypassing of system access restrictions designed to protect end-users from malicious web content. By successfully exploiting this flaw, a remote attacker can deliver phishing pages or drive-by download attempts without triggering the standard Safebrowsing warnings or blocks that would normally alert the user or halt the navigation. This undermines the trust model of the browser and exposes users to social engineering attacks and malware infections that rely on deceptive websites appearing legitimate within the browsing context. Although the severity is rated low, the ability to bypass safety checks remains a critical concern for enterprise environments where web filtering policies are strictly enforced to maintain network integrity and data security posture.
In terms of industry standards classification, this vulnerability aligns with CWE-20 Improper Input Validation as it involves the failure to adequately verify inputs or internal states before processing them within a security-critical function. Furthermore, from an offensive cybersecurity framework perspective such as MITRE ATT&CK, this flaw facilitates techniques related to Initial Access and Defense Evasion by allowing malicious content to bypass automated detection systems that rely on browser-level safety features. The exploitation vector is classified as remote via the network with user interaction required, placing it within common attack patterns observed in web-based exploit campaigns targeting modern browsers.
To mitigate the risks associated with this vulnerability, organizations must ensure that all instances of Google Chrome are updated to version 153.0.8010.36 or later where these state validation checks have been corrected and hardened against such bypass attempts. For environments unable to immediately patch due to compatibility constraints, implementing strict web content security policies through enterprise management tools can help restrict the execution of untrusted scripts and limit navigation capabilities for high-risk users. Additionally, deploying endpoint detection and response solutions that monitor for anomalous browser behavior or unauthorized network connections originating from Chrome processes can provide an additional layer of defense against exploits leveraging this specific logic flaw. Regular auditing of browser configurations and adherence to vendor security advisories remain essential practices for maintaining a robust web browsing security posture.