Description

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

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "6.7",
  "pubDate": "2026-08-11T17:19:10.900Z",
  "pubdate": "2026-08-11T17:19:10.900Z",
  "executiveSummary": "This vulnerability is classified as a heap-based buffer overflow affecting the Windows DNS component. The security flaw enables an authorized threat actor to execute arbitrary code and achieve local privilege escalation on targeted systems. The presence of this vulnerability introduces significant risk to organizational assets, as a compromised local context can be leveraged to attain higher-level operating system privileges, potentially leading to complete system takeover. Successful exploitation requires the attacker to have prior local access and authorization to interact with the vulnerable service. The core issue stems from improper memory management within the affected component when processing specific operational requests, allowing memory corruption to occur. Mitigation relies on applying official security updates provided by the vendor, as no alternative workarounds are inherently detailed beyond standard patch deployment.",
  "technicalDetails": "The vulnerability resides within the Windows DNS component, specifically involving memory allocation and boundary enforcement during data processing routines. The root cause is a heap-based buffer overflow, which occurs when the application fails to adequately validate the size of input data before writing it to a dynamically allocated heap buffer. An authorized attacker with local access can interact with the vulnerable component by supplying maliciously crafted inputs designed to exceed the bounds of the designated memory buffer. As the input data is processed, the surplus bytes overflow the heap boundaries, corrupting adjacent memory structures, function pointers, or control data within the heap segment. By meticulously engineering the overflow payload, the attacker can hijack the execution flow of the process. Because the vulnerable service typically operates with elevated system privileges, successful memory corruption and subsequent code execution allow the attacker to inherit those elevated privileges. The attack flow requires the adversary to establish a local execution context, authenticate or utilize existing local authorization mechanisms, and trigger the vulnerable DNS function with the crafted payload. Post-exploitation impact includes local privilege escalation, unauthorized access to sensitive system resources, and potential persistence mechanisms established within the operating system environment. The vulnerability is local in nature, meaning network exposure is not a primary vector, and exploitation is contingent upon the attacker already possessing local execution capabilities on the target host."
}