Description

Untrusted pointer dereference in Windows Win32K allows an authorized attacker to disclose information locally.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.5",
  "pubDate": "2026-08-11T17:18:34.040Z",
  "pubdate": "2026-08-11T17:18:34.040Z",
  "executiveSummary": "This vulnerability report addresses an untrusted pointer dereference security flaw residing within the Windows Win32K component.\nThe primary impact of this vulnerability is local information disclosure, allowing an unauthorized or locally authenticated threat actor to read sensitive memory contents.\nThe affected product is the Windows operating system, specifically targeting the kernel-mode Win32K subsystem.\nThe risk implications involve the potential leakage of critical kernel memory addresses or sensitive data structures, which could be leveraged by an attacker to facilitate more complex, multi-stage exploitation chains, such as bypassing kernel-level mitigations like KASLR (Kernel Address Space Layout Randomization).\nTo successfully exploit this vulnerability, the attacker must already possess local execution capabilities on the target system.\nSpecific exploitation requirements involve interacting with the vulnerable Win32K subsystem through crafted system calls or user-mode APIs that improperly validate pointers before dereferencing them in kernel space.",
  "technicalDetails": "The vulnerability is rooted in an untrusted pointer dereference condition within the Windows Win32K kernel-mode component.\nThe vulnerable component fails to adequately validate or sanitize pointer values supplied from user mode or derived from untrusted contexts prior to performing memory dereference operations.\nBecause Win32K operates within kernel space (RING 0), improper handling of pointers allows user-supplied data to dictate memory access targets or offsets without rigorous boundary and validity checks.\nThe attack flow begins when a locally authenticated attacker executes a custom user-mode application or script designed to interact with the Win32K subsystem.\nThe attacker initiates specific graphical or window management system calls that pass manipulated parameters or specially structured buffers containing untrusted pointer references.\nUpon receiving the request, the vulnerable Win32K driver processes the input and dereferences the untrusted pointer without ensuring it points to a valid, authorized memory region within the expected context.\nThis flawed dereference operation results in the kernel inadvertently reading out-of-bounds data or sensitive kernel memory contents.\nThe payload behavior focuses on extracting the disclosed memory contents back to user space, where the attacker can analyze the leaked data.\nThe post-exploitation impact centers on local information disclosure, enabling the adversary to map kernel memory layouts, identify critical data structures, and potentially defeat security mitigations such as KASLR.\nAuthentication requirements dictate that the attacker must have local access to the system, while privilege requirements depend on the specific Win32K API surface utilized, though local execution is strictly necessary as the vulnerability does not support remote network exposure."
}