CVE-2026-50401 in Windows
Summary
by MITRE • 07/14/2026
Out-of-bounds read in Windows Cloud Files Mini Filter Driver allows an authorized attacker to disclose information locally.
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Analysis
by VulDB Data Team • 07/15/2026
This vulnerability exists within the Windows Cloud Files Mini Filter Driver, which operates at the kernel level to manage file system operations for cloud storage integration. The flaw manifests as an out-of-bounds read condition that occurs when processing specific file operations through the mini filter framework. An authorized local attacker with standard user privileges can exploit this weakness by crafting malicious file system requests that trigger the driver to access memory locations beyond the intended buffer boundaries. This type of vulnerability falls under the common weakness enumeration CWE-125, which specifically addresses out-of-bounds read conditions in software implementations.
The operational impact of this vulnerability is significant as it enables information disclosure attacks where an attacker can potentially read sensitive kernel memory contents that should remain confidential. The mini filter driver architecture processes file system requests before they reach the core operating system components, making this attack vector particularly dangerous for local privilege escalation scenarios. Attackers can leverage this weakness to extract system information, credentials, or other sensitive data stored in memory regions accessible through the flawed driver interface. This vulnerability directly maps to the ATT&CK technique T1059.001 for command and scripting interpreter and T1068 for exploit for privilege escalation within the Windows operating system attack framework.
The technical exploitation requires an attacker to have legitimate access to the target system, typically through a standard user account or compromised credentials. The attack vector involves triggering specific file operations that cause the driver to process malformed input data, leading to memory corruption and information disclosure. This vulnerability demonstrates poor bounds checking within the driver's processing logic where input validation fails to properly verify buffer limits before accessing memory locations. The mini filter driver's role in intercepting and modifying file system operations makes it a prime target for attackers seeking to escalate privileges or extract sensitive information from the kernel space.
Mitigation strategies should include applying Microsoft security updates promptly, which typically contain patches that address the specific bounds checking issues within the Cloud Files Mini Filter Driver. Organizations should also implement robust access controls and monitoring systems to detect unusual file system activity patterns that might indicate exploitation attempts. Network segmentation and least privilege principles can limit the potential impact of successful exploitation by restricting access to sensitive systems. System administrators should monitor for unauthorized local access attempts and maintain updated threat intelligence regarding similar vulnerabilities in the Windows kernel driver ecosystem. The vulnerability underscores the importance of proper input validation and bounds checking in kernel-level components, particularly those handling user-supplied data through file system interfaces that operate with elevated privileges.