CVE-2026-80093 in Windows
Summary
by MITRE • 09/09/2026
Use after free in Windows Cloud Files Mini Filter Driver allows an authorized attacker to elevate privileges locally.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 09/09/2026
The vulnerability identified as a use-after-free condition within the Windows Cloud Files Mini Filter Driver represents a critical security flaw that compromises the integrity of the operating system's memory management subsystems. This specific driver is responsible for intercepting file I/O operations and providing functionality related to cloud storage integration, allowing applications to interact with remote data stores as if they were local files. The core technical issue stems from improper handling of object lifecycles within the kernel-mode code. Specifically, after a pointer to an allocated memory structure is freed or released by the system, subsequent execution paths in the driver fail to verify whether this pointer remains valid before dereferencing it. This lapse allows the application to access and manipulate memory that has already been returned to the pool for reuse, creating a classic use-after-free scenario where stale pointers are utilized during active operations.
From an operational perspective, this flaw enables local privilege escalation by unauthorized or authorized attackers who have gained initial foothold within the system environment. By carefully crafting specific file I/O requests and timing their execution precisely, an attacker can exploit the race condition inherent in the use-after-free state to overwrite critical kernel data structures. This manipulation allows the injection of arbitrary code into the kernel space or the modification of security tokens associated with the current process. Consequently, the attacker can bypass standard access control mechanisms and elevate privileges from a low-privileged user account to that of SYSTEM or other high-level administrative roles. The impact is severe as it grants complete control over the affected Windows host, facilitating data exfiltration, persistence installation, lateral movement within enterprise networks, and potential denial-of-service conditions through system instability caused by kernel corruption.
This vulnerability aligns with Common Weakness Enumeration (CWE) category CWE-416, which defines use-after-free errors as a distinct class of software weaknesses resulting from the failure to properly manage memory deallocation and subsequent pointer invalidation. In terms of offensive security frameworks, this exploit vector corresponds to MITRE ATT&CK technique T1055, specifically sub-techniques related to process injection or kernel-level code execution such as T1055.012 for Kernel Process Injection. The exploitation requires local access and typically involves sophisticated payload construction to ensure the freed memory is reallocated in a controlled manner that supports the attacker's objectives, making it a high-value target for advanced persistent threats seeking initial foothold expansion within hardened environments.
Mitigation strategies primarily rely on timely application of vendor-provided security patches that address the underlying code defects by implementing proper null-checks and pointer invalidation after memory release operations. System administrators should ensure that all Windows systems are updated with the latest cumulative updates released by Microsoft, which typically include fixes for such kernel-level vulnerabilities in affected components like cloud files mini filter drivers. Additionally, enforcing strict least-privilege principles limits the potential impact of exploitation by restricting user accounts from executing arbitrary code or accessing sensitive system resources. Deploying endpoint detection and response solutions that monitor for anomalous memory access patterns or unexpected privilege escalation events can also provide early warning indicators of attempted exploitation attempts in real-time environments.