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": "2026-08-11T17:18:22.503Z",
  "pubdate": "2026-08-11T17:18:22.503Z",
  "executiveSummary": "A heap-based buffer overflow vulnerability exists within Windows Message Queuing (MSMQ), a component of the Windows operating system.\nThe vulnerability allows an authorized local attacker to achieve privilege escalation on vulnerable systems.\nSuccessful exploitation compromises the integrity and confidentiality of the host operating system by enabling the execution of arbitrary code with elevated privileges.\nThe flaw stems from improper memory management within the MSMQ service when processing specific messages or input data.\nExploitation requires the attacker to have local access and authorization to interact with the Windows Message Queuing service.\nThe risk implication is severe, as local privilege escalation frequently serves as a critical phase in a broader cyber attack chain, enabling attackers to bypass standard security controls, install persistence mechanisms, and access sensitive system resources.",
  "technicalDetails": "The vulnerability is classified as a heap-based buffer overflow residing within the Windows Message Queuing (MSMQ) component.\nThe root cause of the vulnerability involves insufficient bounds checking and memory validation when handling data structures allocated on the heap.\nWhen the MSMQ service processes maliciously crafted message inputs or control requests, it fails to accurately calculate the required buffer size, leading to a memory corruption condition.\nAn authorized local attacker can interact with the MSMQ service by submitting specially crafted input designed to exceed the boundaries of the allocated heap buffer.\nBy overflowing the target heap chunk, the attacker can overwrite adjacent heap metadata or critical application data structures.\nThis memory corruption can be manipulated to redirect control flow, allowing the execution of arbitrary payload instructions within the context of the vulnerable service process.\nBecause the MSMQ service typically operates with elevated system privileges, successful code execution results in immediate local privilege escalation.\nThe attack vector is strictly local, requiring the attacker to possess prior authorization to interact with the message queuing interface.\nNo specific network exposure is required for this phase of the attack, as the flaw resides in local inter-process communication and service handling mechanisms.\nFollowing successful exploitation, the attacker achieves post-exploitation capabilities including administrative or system-level control over the operating system, facilitating further compromise of the host environment."
}