CVE-2026-102208 in Windows
Summary
by MITRE • 10/13/2026
Use after free in Windows Win32 Kernel Subsystem allows an authorized attacker to elevate privileges locally.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 10/13/2026
The vulnerability described involves a use-after-free error within the Windows Win32 Kernel Subsystem, specifically affecting components responsible for managing user-mode and kernel-mode interactions. This class of memory corruption flaw occurs when a program continues to use a pointer after the memory it points to has been freed or reallocated. In the context of the Windows operating system architecture, such errors are particularly critical because they reside in high-privilege execution contexts where direct manipulation of memory structures can bypass standard security controls. The Win32 subsystem serves as a crucial bridge between user applications and the underlying kernel, handling various system calls and object management tasks. When an internal data structure is freed but not properly nullified or when references to it are retained by other active processes or threads, subsequent access attempts result in undefined behavior that can be exploited for malicious purposes.
From a technical perspective, this vulnerability allows an authorized attacker with local access on the system to escalate privileges from their current user context to higher levels, potentially achieving SYSTEM-level control over the machine. The exploitation mechanism typically involves crafting specific inputs or triggering specific sequences of operations that cause the kernel to dereference a dangling pointer pointing to attacker-controlled memory. By carefully controlling the content written into the freed memory region before it is accessed again, an attacker can manipulate critical kernel data structures such as access tokens, process control blocks, or exception handlers. This manipulation enables the execution of arbitrary code in ring 0, which corresponds to the highest privilege level on x86 architectures, thereby granting complete administrative rights over the compromised system.
The operational impact of this vulnerability is severe due to its potential for local privilege escalation without requiring physical access or remote network interaction. Once an attacker gains elevated privileges, they can install rootkits, disable security software, exfiltrate sensitive data, and pivot to other systems within a corporate network. The existence of such flaws in core subsystems like Win32 underscores the complexity of maintaining memory safety in large-scale operating system codebases written primarily in C and assembly languages where manual memory management is prevalent. These vulnerabilities often remain undetected for extended periods until discovered through fuzzing, formal verification efforts, or exploitation by threat actors targeting high-value environments.
Industry standards classify this type of flaw under CWE-416, Use After Free, which highlights the failure to properly manage object lifecycles and pointer validity. In terms of offensive security frameworks like MITRE ATT&CK, this vulnerability facilitates techniques associated with Privilege Escalation via Exploitation for Local Elevation, specifically leveraging memory corruption vulnerabilities to gain higher access levels. Mitigation strategies primarily involve applying vendor-supplied patches that address the specific logic errors leading to premature deallocation or lack of pointer validation. Additionally, organizations should enforce strict least-privilege policies to limit the potential impact if such a vulnerability is exploited in unpatched systems. Enabling advanced protection mechanisms like Kernel Patch Protection and Memory Integrity can also help mitigate exploitation attempts by restricting modifications to critical kernel structures even if an attacker manages to trigger the underlying memory corruption condition.