CVE-2026-87547 in Chrome
Summary
by MITRE • 09/09/2026
Incorrect reference resolution in FileSystem in Google Chrome prior to 153.0.8010.36 allowed a remote attacker leveraging 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 as an incorrect reference resolution within the FileSystem API of Google Chrome prior to version 153.0.8010.36 represents a significant breach in browser isolation mechanisms. This flaw stems from improper handling of file path references, which allows for directory traversal or unauthorized access to resources that should remain inaccessible under normal sandboxing protocols. The core technical issue lies in the failure to correctly validate and resolve relative paths against the intended base directory context. When an attacker crafts a malicious HTML page containing specific JavaScript calls to the FileSystem API, they can manipulate these references to escape the restricted environment where web content is typically confined. This misconfiguration effectively bypasses the security boundaries established by the browser's sandboxing architecture, which is designed to prevent arbitrary code execution and limit the impact of potential exploits on the underlying operating system.
From a technical perspective, this vulnerability aligns with CWE-20 Improper Input Validation and potentially CWE-754 Incorrect Check or Calculation of Special Element Numbers in Dynamic HTML if it involves DOM manipulation leading to path traversal. The attack vector relies heavily on social engineering tactics, requiring the victim user to visit a maliciously crafted webpage that triggers the flawed reference resolution logic. Once triggered, the attacker can leverage this escape from the sandbox to execute arbitrary code with higher privileges than those granted to standard web content. This escalation of privilege is particularly dangerous because it undermines one of the primary defenses against remote exploitation: the principle of least privilege enforced by browser sandboxes. The ability to run code outside these constraints means that malware, keyloggers, or other malicious payloads can interact directly with system resources without being intercepted or restricted by browser security policies.
The operational impact of this vulnerability is severe for end-users who rely on Chrome for secure web browsing and sensitive transactions. An attacker successfully exploiting this flaw could gain full control over the affected user's environment within the context of the compromised process, potentially leading to data theft, installation of persistent backdoors, or use of the machine as part of a botnet. The medium severity rating assigned by Chromium reflects the complexity required for exploitation and the reliance on social engineering, but it does not diminish the potential damage once the sandbox barrier is breached. Organizations using Chrome must recognize that even medium-severity vulnerabilities can lead to critical security incidents if they allow escape from isolation boundaries.
Mitigation strategies primarily involve immediate patching of all affected instances of Google Chrome to version 153.0.8010.36 or later, where these reference resolution issues have been corrected through improved input validation and stricter path normalization checks. In addition to software updates, security awareness training is crucial for users to recognize social engineering attempts that might lead them to visit malicious sites designed to exploit this specific flaw. Network-level controls such as web filtering proxies can also help by blocking access to known malicious domains or detecting anomalous traffic patterns associated with drive-by download attacks targeting browser vulnerabilities. Furthermore, enabling automatic updates ensures that security patches are applied promptly without requiring manual intervention from end-users, thereby reducing the window of exposure during which this vulnerability could be exploited.