Description

Use after free in Windows Win32K allows an authorized attacker to elevate privileges locally.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.0",
  "pubDate": "2026-08-11T17:18:55.540Z",
  "pubdate": "2026-08-11T17:18:55.540Z",
  "executiveSummary": "This vulnerability is classified as a Use After Free (UAF) memory corruption flaw affecting the Windows Win32K component.\nThe primary impact of this security defect is local privilege escalation (LPE), allowing a compromised low-privileged execution context to achieve arbitrary code execution at higher privilege levels, typically system or kernel level.\nThe affected system component is the Windows Win32K kernel-mode driver, which handles core graphical user interface operations and window management.\nThe risk implications are severe, as successful exploitation compromises the foundational security boundary of the operating system, enabling attackers to bypass access controls, install persistent malware, or manipulate sensitive kernel data structures.\nAttacker capabilities are restricted to local execution, requiring the adversary to already possess authenticated access to the target host system and the ability to execute unprivileged code.\nExploitation requirements include local interactive or programmatic access to the host, followed by the execution of a specially crafted payload designed to interact with the vulnerable Win32K subsystem APIs to trigger the memory lifecycle anomaly.",
  "technicalDetails": "The vulnerability resides within the memory management logic of the Windows Win32K kernel-mode driver, specifically in how object lifecycles and references are tracked and released.\nA Use After Free condition occurs when an application continues to utilize a memory pointer after the underlying dynamic memory allocation has been freed or deallocated.\nIn the context of the Win32K component, this typically manifests through complex GUI object interactions where a specific window, menu, or graphical resource is prematurely released while internal kernel references or user-mode callbacks still point to the stale memory address.\nThe attack flow begins when an authenticated, low-privileged local user executes a specially crafted binary or script designed to interact with specific Win32K system calls.\nThe attacker induces a state where a target kernel object is allocated and subsequently freed while maintaining a dangling reference.\nBy performing heap feng-shui or heap grooming techniques, the attacker attempts to reallocate the newly freed heap chunk with controlled data, such as fake object structures or shellcode pointers.\nWhen the Win32K component subsequently accesses the dangling pointer, it dereferences the attacker-controlled data, treating it as a legitimate kernel object.\nThis execution flow redirection allows the attacker to achieve arbitrary kernel read/write capabilities or direct control flow hijacking.\nPost-exploitation impact includes the modification of system token structures, disabling security monitoring mechanisms, and executing arbitrary payloads with kernel-level privileges.\nAuthentication requirements are minimal regarding network exposure, as the flaw is entirely local and non-network-accessible, but the attacker must possess valid local execution capabilities and authorization to interact with the Windows desktop session."
}