CVE-2026-87487 in Chrome
Summary
by MITRE • 09/09/2026
Missing authorization in FileSystem in Google Chrome prior to 153.0.8010.36 allowed a remote attacker who had compromised the renderer process and leveraged social engineering to potentially execute arbitrary code outside the sandbox via a crafted HTML page. (Chromium security severity: Medium)
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability identified in Google Chrome prior to version 153.0.8010.36 represents a critical failure in access control mechanisms within the browser's file system handling subsystems. This flaw, classified under CWE-269 as Improper Privilege Management or more specifically CWE-427 for Uncontrolled Search Path Element depending on the specific vector exploited, allows an attacker to bypass intended security restrictions when interacting with local resources. The core technical issue stems from a missing authorization check that fails to validate whether the requesting process has legitimate permission to access specific file system paths or operations. In modern browser architectures like Chromium, this is particularly dangerous because it undermines the sandboxing model designed to isolate untrusted content from sensitive host systems.
The operational impact of this vulnerability relies heavily on the attacker's ability to first compromise a renderer process through social engineering tactics such as phishing or drive-by downloads. Once inside the isolated renderer environment, which typically lacks direct access to the operating system kernel and critical user files due to sandboxing restrictions, an actor can leverage this missing authorization flaw to escalate privileges beyond the browser's security boundary. By crafting a malicious HTML page that triggers specific file system APIs without proper permission verification, the attacker can execute arbitrary code outside of the sandboxed environment. This effectively neutralizes one of the primary defenses against remote code execution attacks in web browsers.
From an industry standards perspective, this vulnerability aligns with MITRE ATT&CK technique T1059 Command and Scripting Interpreter if it leads to script execution or T1203 Exploitation for Client Execution when targeting user systems directly. It also reflects weaknesses often associated with CWE-78 Improper Neutralization of Special Elements used in an OS Command, particularly if the file system interaction allows injection into underlying shell commands. The severity is rated as Medium by Chromium security teams because while it requires initial compromise via social engineering to reach the renderer stage, the subsequent escape from sandboxing significantly increases the potential for full system takeover or data exfiltration.
Mitigation strategies primarily involve applying the vendor-provided patch that updates Chrome to version 153.0.8010.36 or later, which includes corrected authorization checks within the file system handling code paths. Organizations should ensure automated update mechanisms are enabled for all endpoints running this browser software. Additionally, security awareness training is crucial to reduce the success rate of social engineering attacks that serve as the initial vector for exploiting renderer process compromises. Implementing strict content security policies and disabling unnecessary JavaScript features can further limit the attack surface available to potential adversaries attempting to exploit file system interactions within web pages.