Description

Improper access control in Windows Kernel allows an authorized attacker to elevate privileges locally.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.8",
  "pubDate": "2026-08-11T17:18:56.367Z",
  "pubdate": "2026-08-11T17:18:56.367Z",
  "executiveSummary": "An improper access control vulnerability has been identified within the Windows Kernel, posing significant security risks to affected systems. This flaw allows an authenticated local attacker to execute arbitrary actions and successfully elevate privileges to a higher integrity level, potentially achieving SYSTEM-level access.\nThe vulnerability affects the core architecture of the Windows Kernel, impacting the underlying operating system's capability to properly enforce security descriptors and restrict unauthorized resource access. The primary risk implication involves total system compromise, as successful exploitation grants the adversary unrestricted control over the operating system, bypassing standard discretionary access control lists (DACLs) and security boundaries.\nExploitation of this vulnerability requires local access to the target host and prior authentication, meaning an adversary must already possess a valid user session or the ability to execute code on the local machine through secondary vectors such as spear-phishing or prior initial access. There are no remote exploitation vectors associated with this specific flaw. Security analysts classify the severity as high due to the potential for complete local privilege escalation, enabling threat actors to bypass security controls, tamper with critical system files, install persistent malware, or pivot to other systems within a networked environment.",
  "technicalDetails": "The root cause of the vulnerability stems from improper access control enforcement within the Windows Kernel. Specifically, the kernel fails to adequately validate user-supplied input or correctly enforce permission checks when processing specific system calls or interacting with internal kernel objects and data structures. This validation failure allows low-privileged users to manipulate objects or memory spaces that should typically be restricted to administrative or system-level contexts.\nThe vulnerable component resides directly within the Windows Kernel executable, which is responsible for managing system resources, hardware interactions, and core security reference monitors. Since the flaw involves local privilege escalation, the network exposure is strictly local, and remote execution is not possible. Authentication and authorization requirements dictate that the attacker must possess valid local execution capabilities, starting with a standard, unprivileged user account or context.\nThe attack flow proceeds in a structured sequence. First, the authenticated attacker establishes execution on the target system using a low-privileged security context. Second, the attacker interacts with the Windows Kernel by invoking specific system calls or leveraging exposed interfaces that exhibit the improper access control flaw. Third, by supplying specially crafted parameters or leveraging race conditions and object manipulation techniques, the attacker bypasses the insufficient validation checks enforced by the kernel.\nDuring payload behavior and post-exploitation, the kernel incorrectly grants the attacker heightened permissions, allowing the manipulation of internal token structures or kernel memory. Through token stealing or direct manipulation of process integrity levels, the local attacker elevates their execution context to NT AUTHORITY\\SYSTEM. Once this elevated privilege is achieved, post-exploitation impact includes the execution of arbitrary administrative commands, the disabling of endpoint detection and response (EDR) solutions, the dumping of clear-text credentials from memory via tools like Mimikatz, and the establishment of persistent backdoors to ensure long-term access to the compromised Windows system."
}