Description

Use after free in Windows Kernel allows an authorized attacker to elevate privileges locally.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.0",
  "pubDate": "2026-08-11T17:18:27.240Z",
  "pubdate": "2026-08-11T17:18:27.240Z",
  "executiveSummary": "This vulnerability is classified as a use-after-free weakness residing within the Windows Kernel. The security flaw allows an authorized local attacker to execute arbitrary code and achieve local elevation of privileges on target systems.\nThe affected product is the Windows Kernel, which forms the core of the operating system architecture and handles critical memory management and hardware interaction. Because the vulnerability exists within a privileged kernel-mode component, successful exploitation compromises the foundational security boundary of the operating system.\nThe risk implications are severe, as a low-privileged local user can escalate their security context to the highest privilege level, typically SYSTEM, enabling complete control over the compromised machine, installation of unauthorized software, data exfiltration, or system disruption.\nAttacker capabilities require local access to the system with some level of authorization, though the execution context can start from a standard, non-administrative user account. Exploitation requirements necessitate the ability to execute code locally on the target operating system to interact with the vulnerable kernel component and manipulate heap memory structures.",
  "technicalDetails": "The root cause of the vulnerability stems from a use-after-free condition in the Windows Kernel. A use-after-free occurs when memory is dynamically allocated, subsequently freed, but a pointer to that memory address is retained and accessed later without proper nullification or state validation.\nThe vulnerable component involves internal kernel-mode memory management routines handling specific object lifecycles. When an object is deallocated, incorrect synchronization or reference counting allows a thread to retain a dangling pointer to the reclaimed memory chunk.\nRegarding authentication and privilege requirements, the attack requires local access to the system and an authorized execution capability. Network exposure is non-existent for direct exploitation, as the attack surface is exposed locally through kernel interfaces, device drivers, or system calls.\nThe attack flow proceeds in a structured sequence. First, the attacker initializes interaction with the vulnerable kernel component using documented or undocumented system mechanisms. Next, the attacker induces a state where a specific kernel object is allocated and subsequently freed while maintaining a reference to it. By strategically manipulating the heap—often referred to as heap grooming or heap feng-shui—the attacker causes the memory allocator to reuse the freed memory region for a different, attacker-controlled object or structure containing function pointers.\nWhen the kernel subsequently attempts to access the dangling pointer, it dereferences the newly allocated attacker-controlled data instead of the original object. If function pointers or critical control data within the reclaimed memory have been modified, the instruction pointer can be hijacked upon execution of the callback or method.\nThe post-exploitation impact includes arbitrary code execution in ring 0 (kernel mode), bypassing security controls, disabling security software, establishing persistence, and achieving full local elevation of privileges to SYSTEM."
}