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": "2026-08-11T17:18:15.770Z",
  "pubdate": "2026-08-11T17:18:15.770Z",
  "executiveSummary": "This vulnerability is classified as a Use-After-Free (UAF) memory corruption flaw residing within the Windows Kernel. Successfully exploiting this security weakness allows a locally authenticated attacker to execute arbitrary code with elevated privileges, effectively achieving local privilege escalation (LPE) on vulnerable systems.\nThe risk implications are severe, as an adversary who has gained standard user access to a target machine can leverage this flaw to subvert the operating system's security boundaries, compromise the underlying kernel space, and attain complete administrative control. The primary prerequisite for successful exploitation is that the attacker must already possess local access and the capability to execute code on the target system.\nThe vulnerability affects the core Windows Kernel components responsible for dynamic memory management. Due to improper handling of object references and memory deallocation cycles, a dangling pointer condition is created. If an attacker can manipulate the heap state to reclaim the freed memory with maliciously crafted data, interacting with the original pointer results in arbitrary code execution within kernel context.\nOrganizations relying on affected Windows systems face significant risk if local users or untrusted processes can execute code, necessitating prompt application of vendor-supplied security updates and implementation of defense-in-depth measures to restrict unauthorized local execution.",
  "technicalDetails": "The vulnerability stems from a classic Use-After-Free (UAF) condition within the Windows Kernel. A UAF vulnerability occurs when a program continues to use a pointer after the memory region it references has been deallocated or freed. In the context of the Windows Kernel, this typically involves kernel-mode objects, driver communications, or system callbacks where object reference counts are improperly managed during concurrent operations or error handling paths.\nThe root cause is a synchronization or reference tracking failure within the vulnerable component of the Windows Kernel. When a specific kernel object is slated for destruction, the memory pool associated with it is released. However, one or more references to this object persist in other data structures or execution contexts. Because the pointer is not properly nullified or synchronized, subsequent operations attempt to access the memory address that no longer belongs to the original object.\nThe attack flow proceeds through several distinct phases. First, an authorized attacker with local access initiates interactions with the Windows Kernel, often via system calls, device IOCTLs, or kernel APIs that trigger the allocation and subsequent premature deallocation of the targeted object type. Second, the attacker meticulously grooms the kernel heap to ensure that the newly freed memory chunk is rapidly reallocated and controlled by user-supplied data or a specialized payload. Third, the attacker triggers the execution path that references the dangling pointer. Because the memory block now contains attacker-controlled data structured to mimic valid kernel objects, the kernel processes the forged vtable or function pointers.\nExploitation prerequisites require the attacker to be authenticated locally on the target system, possessing standard user privileges and the ability to execute native binaries. The vulnerability is local in nature and is not directly exploitable over the network unless combined with a separate remote code execution vector. The payload behavior under successful exploitation conditions bypasses user-mode security controls by executing arbitrary instructions within the kernel address space, enabling the modification of process token structures (such as substituting the current token with that of System) and granting full administrative privileges to the attacker's process."
}