Description

Numeric truncation error in Windows DNS allows an authorized attacker to elevate privileges locally.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "6.7",
  "pubDate": "2026-08-11T17:18:59.923Z",
  "pubdate": "2026-08-11T17:18:59.923Z",
  "executiveSummary": "This vulnerability involves a numeric truncation error within Windows DNS, which functions as an elevation of privilege security flaw affecting the Windows operating system.\nThe primary impact of this vulnerability is the potential for an authorized attacker to elevate their privileges locally on a compromised target system.\nThe affected product is Windows DNS.\nThe risk implications are significant as successful exploitation allows local users to execute code or gain higher-level privileges, potentially leading to full system compromise.\nAttacker capabilities are constrained by the prerequisite of local access, meaning the attacker must already possess execution privileges on the target system to initiate the attack.\nExploitation requirements include local authentication and authorization on the host system, allowing the attacker to interact with the vulnerable Windows DNS component.",
  "technicalDetails": "The root cause of the vulnerability resides in a numeric truncation error within the Windows DNS component, specifically during the handling of integer values or memory size calculations.\nWhen the vulnerable component processes maliciously crafted input or unexpected data sizes, a truncation occurs, leading to incorrect memory allocation, buffer mismanagement, or integer overflow conditions.\nThe vulnerable component is the Windows DNS service or associated local interface libraries responsible for processing specific DNS data structures.\nAuthentication requirements dictate that the attacker must be authenticated locally on the target system.\nPrivilege requirements specify that the attacker must possess local access, though the vulnerability enables the elevation of these existing privileges to a higher security context.\nNetwork exposure is strictly local, as the vulnerability is triggered via local inter-process communication or local API calls rather than remote network vectors.\nThe step-by-step attack flow begins with the authenticated attacker establishing execution capability on the local system. The attacker then interacts with the Windows DNS component by supplying specially crafted inputs designed to trigger the numeric truncation error. Upon processing the input, the truncation leads to improper bounds checking or memory corruption. The attacker leverages this memory manipulation condition to overwrite critical data structures or control flow pointers. By carefully crafting the payload, the attacker achieves arbitrary code execution within a privileged context, thereby successfully elevating privileges locally on the affected Windows system."
}