CVE-2026-50417 in Windows
Summary
by MITRE • 07/14/2026
Heap-based buffer overflow in Windows NTFS allows an authorized attacker to execute code locally.
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Analysis
by VulDB Data Team • 07/14/2026
This vulnerability represents a critical heap-based buffer overflow flaw within the Windows NTFS file system implementation that enables authenticated local attackers to achieve arbitrary code execution. The vulnerability stems from improper input validation and memory management practices within the ntfs.sys kernel driver responsible for handling NTFS file operations. When legitimate user processes interact with NTFS filesystem structures, particularly during file creation, modification, or access operations, the system fails to properly bounds-check data written to heap-allocated memory regions. This flaw exists in the kernel-level file system driver and affects all supported Windows operating systems including windows 10, windows server 2016, and later versions.
The technical exploitation of this vulnerability occurs when an authenticated user crafts malicious input data that triggers the buffer overflow condition during NTFS file system operations. The heap corruption allows attackers to overwrite critical memory structures or function pointers, potentially enabling code execution with kernel-level privileges. This type of vulnerability directly maps to CWE-122 Heap-based Buffer Overflow which is classified as a high-severity weakness in the Common Weakness Enumeration catalog. The attack vector requires local authentication and does not necessitate network connectivity, making it particularly dangerous in environments where users have legitimate access rights.
From an operational impact perspective, this vulnerability creates a significant security risk for organizations since it allows privilege escalation from standard user accounts to system-level privileges without requiring additional attack vectors. The exploitation can lead to complete system compromise, data exfiltration, persistence mechanisms establishment, and lateral movement within network environments. Security professionals should consider this vulnerability in their threat modeling exercises as it represents a persistent backdoor capability that could be leveraged by both malicious insiders and external attackers who have gained initial access through other means. The vulnerability's impact aligns with ATT&CK technique T1068 for locally executed code and T1543 for privilege escalation.
Mitigation strategies should focus on immediate patch deployment from Microsoft as the primary defense mechanism, combined with network segmentation to limit potential lateral movement. System administrators should implement least privilege principles and monitor for unusual file system activity patterns that might indicate exploitation attempts. Additional protective measures include disabling unnecessary file system features, implementing application whitelisting policies, and conducting regular security audits of file system access controls. Organizations should also consider deploying endpoint detection and response solutions capable of identifying heap corruption indicators and anomalous kernel behavior that may suggest exploitation attempts. The vulnerability demonstrates the importance of kernel-level memory safety practices and highlights the need for comprehensive security testing of core operating system components.