CVE-2026-87435 in Chrome
Summary
by MITRE • 09/09/2026
Information leak in ControlledFrame in Google Chrome prior to 153.0.8010.36 allowed a remote attacker who had compromised the renderer process to obtain sensitive information via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability identified as an information leak within the ControlledFrame component of Google Chrome prior to version 153.0.8010.36 represents a significant breach in browser isolation mechanisms, specifically targeting the boundaries between renderer processes and controlled frame contexts. This flaw allows for the unauthorized exfiltration of sensitive data by leveraging a crafted HTML page executed within an environment where the attacker has already achieved compromise of the renderer process. The severity is classified as Medium by Chromium security standards, indicating that while exploitation requires specific preconditions such as prior code execution or sandbox escape, the potential impact on user privacy and data integrity remains substantial.
From a technical perspective, ControlledFrames are designed to provide isolated environments for rendering content from different origins with varying levels of trust and access privileges. The vulnerability stems from improper state management or permission checks within this component, which inadvertently exposes internal browser states, DOM structures, or memory contents to the compromised renderer context. When an attacker crafts an HTML page that exploits these misconfigurations, they can bypass expected restrictions on cross-origin data access. This allows the malicious script running in the renderer process to read sensitive information that should remain confined to higher-privilege contexts or other tabs, effectively breaking the sandbox model intended to protect user data from untrusted web content.
The operational impact of this vulnerability is primarily centered around privacy violations and potential credential theft if combined with other attack vectors such as cross-site scripting (XSS) or session hijacking techniques. An attacker who has managed to execute arbitrary code within a renderer process, perhaps through a previously exploited zero-day or a malicious extension, can use this flaw to harvest sensitive information from the current browsing context. This could include cookies, local storage data, form inputs containing personal identifiable information (PII), or other dynamic content rendered by the browser. The ability to obtain such data remotely via a crafted page underscores the risk posed when isolation boundaries are weakened, potentially leading to account takeovers or identity theft for affected users.
This incident aligns with Common Weakness Enumeration (CWE) category CWE-200: Information Exposure, which covers scenarios where sensitive information is disclosed without proper authorization controls. Furthermore, in the context of the MITRE ATT&CK framework, this vulnerability facilitates techniques related to Collection and Exfiltration over C2 channels if the attacker combines it with data staging mechanisms. It highlights the critical importance of maintaining strict separation between renderer processes and privileged browser components, ensuring that even if a sandbox is breached, the blast radius remains limited and sensitive user data does not leak into untrusted execution environments.
Mitigation strategies for this vulnerability involve immediate patching to version 153.0.8010.36 or later, which addresses the underlying logic errors in ControlledFrame handling. Organizations should ensure that browser update policies are enforced across all endpoints to minimize exposure windows. Additionally, users and administrators can employ defense-in-depth measures such as disabling JavaScript for untrusted sites using content security policies where applicable, utilizing extensions that enforce strict origin isolation, and keeping operating system-level sandboxing features enabled. Regular auditing of installed browser extensions is also recommended, as compromised or malicious extensions are a common initial vector for renderer process compromise, which serves as the prerequisite condition for exploiting this specific information leak.