Description

Use after free in Windows DHCP Client allows an authorized attacker to execute code locally.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.0",
  "pubDate": "2026-08-11T17:18:11.070Z",
  "pubdate": "2026-08-11T17:18:11.070Z",
  "executiveSummary": "A use-after-free vulnerability exists within the Windows DHCP Client, specifically impacting the handling of dynamic host configuration protocol communications. This memory corruption flaw allows an authorized local attacker to achieve arbitrary code execution on the target operating system.\nThe vulnerability represents a significant security risk because successful exploitation compromises the integrity and confidentiality of the host system. The flaw arises from improper management of dynamic memory allocations during client-server interactions, leading to dangling pointers that can be manipulated by a malicious actor.\nExploitation of this vulnerability requires the attacker to possess local access to the target system and authorization to execute code in that environment. While remote exploitation is not facilitated by this specific vector, local privilege escalation scenarios are a primary concern.\nOrganizations running affected Windows DHCP Client implementations must prioritize remediation efforts. Security implications include potential system compromise, unauthorized execution of privileged instructions, and further lateral movement within the internal network if the affected endpoint serves as a staging asset.",
  "technicalDetails": "The vulnerability is rooted in a use-after-free condition within the Windows DHCP Client component. A use-after-free flaw occurs when the application continues to use a pointer after the memory chunk it references has been deallocated or freed. If the program does not properly nullify the reference pointer following the deallocation, a dangling pointer is established.\nDuring normal operational flows, the Windows DHCP Client processes lease negotiations, renewals, and configuration parameters provided via network packets. When handling specific malformed or unexpected responses, memory structures associated with state tracking or packet parsing are prematurely freed while internal references to these structures remain active.\nAn authorized attacker leveraging local execution capabilities can influence the heap layout and manipulate the contents of the newly freed memory region through heap spraying or grooming techniques. When the vulnerable component subsequently attempts to access the dangling pointer, it interacts with attacker-controlled data instead of the expected structure.\nThis anomalous pointer dereference redirects execution flow to instructions supplied or chosen by the attacker, resulting in arbitrary code execution within the security context of the vulnerable process. Depending on the privileges assigned to the running service or component, the resulting execution may inherit elevated operating system privileges.\nThe attack vector necessitates that the local attacker has already attained a foothold on the target machine with sufficient execution rights to interact with the local environment. Network exposure of the DHCP client is limited to local interface operations or interactions with designated DHCP servers, but the core vulnerability mechanism is triggered through the local memory management failure rather than direct remote packet injection."
}