CVE-2026-69275 in Windows
Summary
by MITRE • 09/08/2026
Use after free in Kernel Streaming WOW Thunk Service Driver allows an authorized attacker to elevate privileges locally.
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Analysis
by VulDB Data Team • 09/08/2026
The vulnerability identified involves a use-after-free condition within the Kernel Streaming Wow Thunk Service Driver, commonly referred to as ksproxy.dll or related kernel-mode components handling 32-bit streaming on 64-bit Windows systems. This specific driver acts as a bridge between user-mode applications and kernel-mode audio devices, facilitating communication for legacy 32-bit multimedia applications running under WOW64 emulation. The core technical flaw stems from improper memory management practices where the driver fails to properly validate pointers after freeing associated memory structures. When an application requests resources or performs operations that trigger deallocation of internal data objects, the driver may retain references to these now-invalid memory addresses. If subsequent code paths attempt to access or manipulate these dangling pointers without checking their validity first, it results in a use-after-free scenario. This class of vulnerability is categorized under CWE-416 and represents one of the most dangerous types of memory corruption errors because it allows an attacker to control what data is written into freed memory regions or how the system interprets that memory during subsequent operations.
The operational impact of this flaw is significant, primarily due to its potential for local privilege escalation. An authorized attacker who has already gained a foothold on the system with standard user privileges can exploit this vulnerability by crafting specific malicious inputs that trigger the use-after-free condition in a controlled manner. By carefully manipulating memory layout and heap structures through repeated allocation and deallocation cycles, an attacker can achieve arbitrary code execution within the kernel space. Since the driver operates at Ring 0 level of privilege, successful exploitation grants the attacker full control over the operating system. This effectively bypasses standard security boundaries such as User Account Control (UAC) and mandatory integrity controls, allowing the adversary to install malware, create new administrative accounts, or exfiltrate sensitive data with unrestricted access. The attack vector is classified under ATT&CK technique T1068 Exploitation for Privilege Escalation, specifically leveraging software vulnerabilities rather than misconfigurations or credential theft.
Mitigation strategies must address both the immediate technical flaw and broader systemic security posture. From a patching perspective, organizations should ensure that all systems are updated with the latest cumulative updates provided by Microsoft, which typically include fixes for such kernel-level memory corruption issues in affected drivers like ksproxy.dll. In environments where immediate patching is not feasible due to compatibility concerns or operational constraints, network segmentation and application whitelisting can help limit the ability of an attacker to execute arbitrary code that triggers this specific driver path. Additionally, enabling advanced protection features such as Kernel Patch Protection (PatchGuard) on 64-bit systems adds a layer of defense by preventing unauthorized modifications to kernel memory structures, although it does not directly prevent use-after-free exploitation if the vulnerability allows for controlled execution flow redirection. Security monitoring should focus on detecting unusual process creation events or attempts to load unsigned drivers, as these are common indicators of privilege escalation attempts following initial compromise. Regular auditing of driver signatures and enforcing strict code signing policies further reduces the attack surface by ensuring that only trusted, verified components interact with critical kernel subsystems.