CVE-2026-93383 in Chrome
Summary
by MITRE • 09/18/2026
Information leak in Permissions in Google Chrome prior to 153.0.8010.52 allowed a remote attacker to leak cross-origin data via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 09/18/2026
The vulnerability identified as an information leak within the permissions system of Google Chrome versions preceding 153.0.8010.52 represents a significant breach in browser isolation mechanisms. This flaw specifically affects how the user agent handles cross-origin data access, allowing a remote attacker to extract sensitive information from one origin and expose it to another unauthorized context. The core technical failure lies in the permission management logic, which failed to strictly enforce boundaries between different web origins during specific interaction sequences involving crafted HTML pages. When a victim visits a maliciously constructed webpage, the browser's internal state regarding permissions is manipulated or misinterpreted, leading to an unintended disclosure of data that should remain confined within its original security context. This type of vulnerability undermines the fundamental principle of same-origin policy, which is designed to prevent documents loaded from one origin from interacting with resources from another origin without explicit permission.
From a technical perspective, this issue aligns closely with CWE-200, which categorizes information exposure vulnerabilities where sensitive data becomes available to unauthorized actors. The attack vector relies on social engineering or drive-by download tactics, requiring the victim to load an HTML page crafted specifically to exploit the race conditions or logic errors in Chrome's permission handling subsystem. By leveraging these flaws, an attacker can bypass standard security checks that are supposed to restrict access to cookies, local storage, DOM elements, and other sensitive APIs associated with a different domain. The severity is classified as medium by the Chromium team because while it does not typically allow for direct code execution or full system compromise, it facilitates sophisticated phishing campaigns, session hijacking, and targeted surveillance of user activities across multiple websites.
The operational impact of this vulnerability extends beyond simple data leakage. It enables attackers to build detailed profiles of users by aggregating information from various sources that were previously isolated. For instance, an attacker could potentially access authentication tokens or personal identifiers stored in local storage on one site while the victim is browsing a malicious page hosted elsewhere. This capability significantly lowers the barrier for advanced persistent threats and state-sponsored actors who rely on stealthy data exfiltration rather than overt disruption. The ability to leak cross-origin data effectively breaks the trust model of the web, forcing users into situations where their privacy is compromised without any explicit consent or notification from the browser interface.
To mitigate this risk, organizations and individual users must prioritize immediate updates to Google Chrome version 153.0.8010.52 or later. This release contains patches that correct the permission handling logic, ensuring stricter enforcement of origin boundaries during cross-origin requests and interactions. Administrators should implement automated patch management systems to ensure rapid deployment across all endpoints within their infrastructure. Additionally, users are advised to exercise caution when visiting unfamiliar websites and to utilize browser extensions that enforce strict content security policies or block potentially malicious scripts where feasible. Monitoring for unusual network traffic patterns originating from the browser process can also serve as an early detection mechanism for exploitation attempts in environments where patching delays might occur.
This incident highlights the ongoing challenges in maintaining robust isolation boundaries within complex software ecosystems like modern web browsers. It reinforces the importance of rigorous code auditing and fuzz testing focused on permission systems, which are critical components of browser security architecture. Future developments should emphasize enhanced sandboxing techniques and more granular control over cross-origin data flows to prevent similar logic errors from being exploited in subsequent versions. The resolution serves as a reminder that even medium-severity vulnerabilities can have profound implications for user privacy and organizational security posture if left unaddressed.