CVE-2026-69916 in Windows
Summary
by MITRE • 10/14/2026
Integer overflow or wraparound in Windows NTFS allows an authorized attacker to elevate privileges locally.
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Analysis
by VulDB Data Team • 10/14/2026
The vulnerability described involves a critical integer overflow condition within the New Technology File System (NTFS) implementation of Microsoft Windows operating systems. This flaw resides deep within the kernel-mode components responsible for managing file system structures, specifically during the processing of metadata operations or volume management tasks. When an authorized user interacts with NTFS volumes through standard application programming interfaces, a miscalculation in how memory addresses or buffer sizes are computed can lead to an integer wraparound. This arithmetic error causes the operating system to allocate insufficient memory for subsequent data structures or misinterpret boundary conditions, creating a discrepancy between expected and actual memory layout. The root cause is typically traced back to inadequate validation of input parameters before they are passed into low-level file system drivers, allowing maliciously crafted inputs to trigger this overflow state during routine file operations such as opening, reading, or writing files on NTFS-formatted drives.
From a technical perspective, the integer overflow allows an attacker who has already gained local access with standard user privileges to manipulate kernel memory in unintended ways. By carefully crafting specific file names, directory structures, or metadata attributes, the attacker can force the system to write data beyond allocated buffer boundaries. This out-of-bounds write capability enables the corruption of critical kernel data structures, such as process control blocks or security descriptors. Once these internal structures are compromised, the integrity checks that normally prevent privilege escalation fail, allowing the malicious code to execute with SYSTEM-level privileges. The exploit relies on precise timing and memory layout manipulation to ensure that the overwritten data results in a controlled execution flow redirect, effectively bypassing user-mode restrictions and gaining full control over the operating system kernel.
The operational impact of this vulnerability is severe due to its potential for local privilege escalation. An attacker with low-privileged access can transform their position into one with complete administrative rights over the affected Windows host. This compromise undermines all security boundaries enforced by the operating system, including those provided by User Account Control (UAC) and mandatory integrity controls. With SYSTEM privileges, an adversary can install persistent backdoors, dump sensitive credentials from memory using tools like Mimikatz, modify or delete critical system files, disable logging mechanisms to cover their tracks, and pivot further into connected network resources. The existence of this flaw significantly lowers the barrier for initial access exploitation, as it does not require remote code execution capabilities but rather only local file system interaction rights which are commonly available in multi-user environments such as corporate workstations or shared servers.
This vulnerability aligns with Common Weakness Enumeration (CWE) category CWE-190, which defines integer overflow or wraparound errors that lead to subsequent memory corruption issues. In the context of the MITRE ATT&CK framework, this flaw facilitates techniques associated with Privilege Escalation via Exploitation for Local Elevation, specifically mapping to tactics involving exploitation of system misconfigurations and kernel vulnerabilities. Mitigation strategies primarily involve applying vendor-supplied security patches that address the underlying arithmetic validation logic within the NTFS driver components. Organizations should prioritize patching affected Windows versions immediately upon release of the update. Additionally, implementing strict application whitelisting can prevent unauthorized execution of exploit code even if the vulnerability is triggered. Network segmentation and least-privilege access policies further reduce risk by limiting which users have write access to sensitive file system locations where such exploits might be staged or executed effectively.