CVE-2026-69461 in Windows
Summary
by MITRE • 09/09/2026
Stack-based buffer overflow in Windows NTFS allows an unauthorized attacker to execute code over a network.
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability described constitutes a critical security flaw within the Microsoft Windows New Technology File System driver, specifically affecting how the system processes certain file attributes and metadata requests transmitted over a network connection. This stack-based buffer overflow arises from improper bounds checking during the parsing of NTFS-specific data structures received via Server Message Block or similar remote protocol interfaces. When an attacker crafts a maliciously formatted request containing oversized or malformed input fields intended for specific NTFS operations, the driver fails to validate the length of this input against the allocated memory space on the stack. Consequently, the excess data overwrites adjacent memory locations that store critical control flow information, such as return addresses and saved frame pointers. This corruption allows an attacker to redirect the execution flow of the affected process, typically a system-level service handling file operations, thereby achieving arbitrary code execution with elevated privileges without requiring any user interaction or authentication credentials in many scenarios.
The operational impact of this vulnerability is severe due to its potential for remote exploitation and privilege escalation. Since NTFS handles fundamental file system interactions, an attacker can leverage this flaw to execute malicious payloads directly on the target machine's kernel mode or high-privilege user-mode processes. This capability effectively grants full control over the compromised host, enabling data exfiltration, installation of persistent backdoors, lateral movement within a networked environment, and complete disruption of system availability. The absence of required authentication makes this vulnerability particularly dangerous in enterprise environments where shared drives are common, as it allows unauthenticated remote attackers to target vulnerable systems across local area networks or even over the internet if exposed services are present.
From a classification perspective, this flaw aligns with CWE-120 Buffer Copy without Checking Size of Input and CWE-787 Out-of-bounds Write in ATT&CK framework contexts related to exploitation for privilege escalation. The attack vector is categorized under Remote Code Execution via Network Protocols, highlighting the risk associated with services that process untrusted input from network sources. Mitigation strategies primarily involve applying vendor-supplied security patches that address the buffer validation logic within the NTFS driver code. Organizations should prioritize patching all affected Windows versions immediately and restrict access to file sharing protocols by implementing strict firewall rules that limit exposure of SMB ports to trusted subnets only. Additionally, deploying intrusion detection systems capable of identifying anomalous packet sizes or malformed protocol structures can provide an additional layer of defense against exploitation attempts while patches are being deployed across the infrastructure.