Description

Heap-based buffer overflow in Windows Shell allows an authorized attacker to elevate privileges locally.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.8",
  "pubDate": "2026-08-11T17:18:29.550Z",
  "pubdate": "2026-08-11T17:18:29.550Z",
  "executiveSummary": "This vulnerability is classified as a heap-based buffer overflow affecting the Windows Shell component. The primary impact of successful exploitation is local privilege escalation, allowing an authenticated attacker to execute arbitrary code with elevated privileges on the target system.\nThe affected product is Windows Shell, which handles core user interface and desktop integration functionalities within Microsoft Windows operating systems. The risk implications are severe, as an adversary who has achieved initial standard access to a compromised host can leverage this flaw to attain higher-level permissions, potentially leading to full system compromise.\nExploitation requirements dictate that the attacker must already possess authorization and local execution capabilities on the target machine. Remote exploitation vectors are not applicable, as the flaw requires local execution context to interact directly with the vulnerable Windows Shell component.",
  "technicalDetails": "The root cause of the vulnerability is a heap-based buffer overflow residing within the Windows Shell component. Specifically, improper bounds checking during the processing of input data within memory allocation operations on the heap allows data to exceed the allocated buffer boundaries, resulting in adjacent memory corruption.\nThe vulnerable component is the Windows Shell, which fails to adequately validate the size of input parameters before copying them into dynamically allocated heap memory structures. The exploitation method involves an authorized local attacker supplying specially crafted input to the vulnerable routines, triggering the heap overflow condition.\nThe attack flow proceeds as follows: First, the local attacker authenticates to the target system with standard user privileges. Second, the attacker interacts with the Windows Shell via local application interfaces or command structures designed to invoke the vulnerable parsing logic. Third, the crafted input is supplied, causing a memory corruption event on the heap where critical control data or function pointers may be overwritten. Finally, execution flow is redirected to attacker-controlled payloads or instructions.\nAuthentication requirements specify that the attacker must be authorized and authenticated locally on the system. Privilege requirements are minimal prior to exploitation, as standard user access is sufficient to interact with the vulnerable component. Network exposure is localized, meaning the vulnerability cannot be exploited remotely over a network interface without prior local execution access.\nThe payload behavior resulting from successful memory corruption involves arbitrary code execution within the context of a privileged process managed by the Windows Shell. The post-exploitation impact includes local privilege escalation, allowing the attacker to bypass standard security controls, access sensitive system resources, install persistent backdoors, or pivot further within the local environment."
}