Description

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

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.8",
  "pubDate": "2026-08-11T17:18:22.153Z",
  "pubdate": "2026-08-11T17:18:22.153Z",
  "executiveSummary": "A heap-based buffer overflow vulnerability exists within Windows Message Queuing, affecting systems where the Message Queuing service is enabled. This memory corruption vulnerability allows an authenticated local attacker to achieve privilege escalation on the target system.\nThe flaw stems from improper bounds checking during the processing of message data within the affected component, leading to memory overwrite conditions on the heap. Successful exploitation of this vulnerability compromises the confidentiality, integrity, and availability of the host operating system, potentially allowing the attacker to execute arbitrary code with elevated privileges.\nExploitation requires the attacker to have local access to the target system and authorization to interact with the Windows Message Queuing service. Given the local privilege escalation impact, successful exploitation could facilitate complete system compromise, enabling attackers to bypass security boundaries, install malicious persistence mechanisms, access sensitive data, or pivot to other systems within the network environment.\nOrganizations utilizing Windows Message Queuing must prioritize remediation by applying official security updates provided by the vendor. In environments where the service is non-essential, disabling the Windows Message Queuing feature entirely serves as an effective defense-in-depth measure to eliminate the attack surface associated with this vulnerability.",
  "technicalDetails": "The vulnerability is characterized as a heap-based buffer overflow residing within the Windows Message Queuing service. This component is responsible for handling message queuing operations, facilitating asynchronous communications, and managing message storage and transmission across applications.\nThe root cause of the vulnerability involves insufficient boundary validation when parsing incoming message payloads or internal data structures within the vulnerable component. When the application allocates a fixed-size buffer on the heap and subsequently copies untrusted input without strictly validating its length, an overflow condition occurs. This allows excess input data to overwrite adjacent memory structures, function pointers, or heap metadata located on the heap.\nExploitation requires the adversary to be authenticated locally on the target host and to possess the capability to interact with the Windows Message Queuing service interfaces. The attack flow initiates when the malicious actor crafts a specially formulated message or sequence of operations designed to exceed the allocated heap buffer size.\nUpon submitting this malicious payload to the vulnerable component, the lack of rigorous size verification results in memory corruption. By meticulously engineering the overflow contents, an advanced attacker can manipulate heap metadata or overwrite critical application data structures. This controlled memory corruption can be leveraged to redirect execution flow to attacker-controlled shellcode or arbitrary instructions.\nBecause the Windows Message Queuing service typically executes with high privileges, successfully hijacking the execution flow grants the attacker the same elevated security context. Post-exploitation impact includes the execution of arbitrary payloads with elevated privileges, granting the adversary administrative control over the local operating system, the ability to disable security controls, manipulate system files, and compromise any local user accounts or resources."
}