Description

Use after free in Windows DWM Core Library allows an authorized attacker to elevate privileges locally.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.8",
  "pubDate": "2026-08-11T17:18:40.030Z",
  "pubdate": "2026-08-11T17:18:40.030Z",
  "executiveSummary": "A use-after-free vulnerability exists within the Windows DWM Core Library, posing significant security risks to affected Windows operating systems. This vulnerability allows an authorized local attacker to execute arbitrary code within the context of a higher privilege level, successfully resulting in local privilege escalation. The flaw resides in the improper management of dynamic memory allocations within the Desktop Window Manager, where a dangling pointer is referenced after the underlying memory object has been deallocated or freed. To successfully exploit this vulnerability, an attacker must already possess local access to the target system and appropriate authorization to interact with the DWM subsystem. The realization of this attack undermines the foundational integrity of operating system security boundaries, potentially allowing malicious actors to bypass standard access controls, manipulate core system processes, and execute unauthorized administrative actions. Given the systemic nature of the Desktop Window Manager in rendering graphical user interfaces and managing desktop compositions, vulnerabilities within this component represent critical vectors for system compromise. Mitigation strategies rely heavily on applying vendor-supplied software updates and security patches designed to correct memory management routines and eliminate dangling pointer references within the DWM Core Library.",
  "technicalDetails": "The vulnerability is characterized as a classic use-after-free (UAF) memory corruption flaw residing in the Windows DWM Core Library. A use-after-free condition occurs when software fails to properly clear or nullify a pointer after releasing the memory resource it references. If the program subsequently attempts to access the memory location via the dangling pointer, unpredictable behavior, memory corruption, or arbitrary code execution can ensue. In the context of the Windows DWM Core Library, this flaw manifests during the lifecycle management of graphical objects, surfaces, or window composition resources processed by the subsystem. The root cause stems from race conditions, improper reference counting, or flawed state synchronization during the allocation, manipulation, and deallocation phases of DWM objects. An authorized local attacker initiates the attack flow by interacting with the DWM API, deliberately triggering a sequence of events that forces the targeted memory object to be freed while maintaining a valid reference to it elsewhere in the execution context. By strategically manipulating heap memory layouts through mass allocations and deallocations—commonly referred to as heap grooming or heap feng shui—the attacker can cause a newly allocated, attacker-controlled object to occupy the exact memory address previously inhabited by the freed DWM structure. When the DWM Core Library subsequently dereferences the dangling pointer to process window composition or rendering tasks, it interacts with the attacker-controlled data instead of the legitimate object. This redirection of execution flow allows the attacker to inject malicious payloads, corrupt critical function pointers, or manipulate internal data structures governing process permissions. Because the DWM Core Library operates with elevated privileges necessary for desktop rendering and hardware acceleration, successful exploitation grants the attacker the ability to execute arbitrary code with these elevated privileges, effectively achieving local privilege escalation. The vulnerability requires local access and authorization, precluding remote network exploitation without prior entry, but poses severe post-exploitation risks within multi-user environments or compromised host scenarios."
}