CVE-2026-50374 in Windows
Summary
by MITRE • 07/14/2026
Use after free in Windows Cloud Files Mini Filter Driver allows an authorized attacker to elevate privileges with a physical attack.
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Analysis
by VulDB Data Team • 07/15/2026
This vulnerability represents a critical use-after-free condition within the Windows Cloud Files Mini Filter Driver component that enables privilege escalation under specific circumstances. The flaw exists in the kernel-mode driver that handles cloud file operations, specifically when processing certain file system filter callbacks. When an authorized attacker with physical access to a target system can manipulate the cloud file filtering process, they can exploit this use-after-free scenario to execute arbitrary code with elevated privileges. The vulnerability stems from improper memory management where freed kernel memory structures are accessed after being reallocated or reused by other processes within the driver's execution context.
The technical implementation of this flaw involves the mini filter driver's handling of file operations in cloud storage environments such as OneDrive or SharePoint integration. During normal operation, the driver maintains internal data structures that track file access patterns and synchronization states between local and remote cloud storage repositories. When malicious input or crafted file operations are processed through these filtering mechanisms, the driver fails to properly validate memory references before accessing previously freed kernel memory locations. This creates an opportunity for attackers to control the execution flow by overwriting critical function pointers or data structures that would normally remain intact.
The operational impact of this vulnerability extends beyond typical privilege escalation scenarios due to its requirement for physical access, which significantly reduces the attack surface but increases the potential damage level. Physical access allows an attacker to leverage both local system exploitation capabilities and potentially hardware-level manipulation techniques such as memory dumping or direct device access. The combination of authorized access and physical presence provides attackers with multiple vectors for achieving their objectives including code injection, credential harvesting, or establishing persistent backdoors within the Windows environment. This vulnerability directly maps to attack patterns described in the mitre att&ck framework under privilege escalation techniques and specifically aligns with tactics involving exploitation of system-level components.
Security implications of this flaw are particularly severe because it operates at the kernel level where standard user-mode protections do not apply. The use-after-free condition can be exploited through carefully crafted file operations that trigger the vulnerable code path, potentially allowing attackers to execute malicious code with SYSTEM privileges. This represents a significant risk in enterprise environments where cloud integration is prevalent and physical security controls may be insufficient. Organizations should consider implementing additional hardware-based security measures such as memory protection features, secure boot configurations, and enhanced physical access controls alongside traditional software patches.
Mitigation strategies for this vulnerability require immediate patch application from Microsoft as part of regular security maintenance procedures. System administrators must ensure that all Windows systems running cloud file integration features receive the relevant security updates promptly. Beyond patch management, organizations should implement monitoring solutions that can detect unusual file system activity patterns associated with cloud file operations and establish network segmentation controls to limit potential lateral movement if exploitation occurs. The vulnerability also highlights the importance of maintaining comprehensive incident response procedures for physical security breaches and kernel-level exploit detection. Security teams should conduct regular assessments of their cloud integration configurations and ensure proper access controls are in place to minimize the risk of unauthorized local system access that could enable exploitation of this class of vulnerability.