CVE-2026-54992 in Windows
Summary
by MITRE • 07/14/2026
Heap-based buffer overflow in Windows Message Queuing Queue Manager allows an unauthorized attacker to execute code locally.
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Analysis
by VulDB Data Team • 07/14/2026
A heap-based buffer overflow vulnerability exists within the Windows Message Queuing Queue Manager component that enables unauthorized attackers to achieve local code execution. This flaw resides in the handling of specially crafted messages within the message queuing system, where insufficient bounds checking allows malicious data to overwrite adjacent memory regions in the heap allocation space. The vulnerability stems from improper input validation when processing queue messages, particularly affecting the way the system manages memory allocations for message buffers and associated metadata structures.
The technical implementation of this vulnerability occurs during the message processing lifecycle where the Queue Manager fails to properly validate the size of incoming message data before copying it into allocated heap memory regions. When an attacker crafts a message with excessive data payload that exceeds the allocated buffer size, the excess data overflows into adjacent heap memory locations, potentially corrupting critical data structures or executable code pointers. This type of vulnerability is classified as CWE-121 heap-based buffer overflow and represents a critical security weakness in the Windows messaging infrastructure that can be exploited through local system access.
From an operational perspective, this vulnerability presents significant risk to systems running Windows Message Queuing services, particularly those with multiple users or applications relying on message queuing for inter-process communication. The attack requires local system access but does not necessitate network exposure, making it particularly dangerous in environments where privilege escalation opportunities exist. Attackers can leverage this vulnerability to execute arbitrary code with the privileges of the affected service account, potentially leading to complete system compromise. The impact extends beyond immediate code execution as the corrupted heap memory can cause system instability, application crashes, or further exploitation through chained vulnerabilities.
Security professionals should implement multiple layers of defense including immediate patch deployment for the identified vulnerability through Microsoft security updates, along with network segmentation to limit local access points to systems running message queuing services. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques, specifically targeting the 'Exploitation for Privilege Escalation' tactic where attackers leverage local vulnerabilities to gain elevated system privileges. Additional mitigations include implementing least privilege principles for message queue service accounts, enabling Windows Defender Application Control policies to restrict unauthorized code execution, and monitoring for anomalous message queuing activities that might indicate exploitation attempts. Regular security assessments should focus on identifying systems running outdated message queuing components and ensuring proper access controls are implemented to prevent unauthorized local system access that could enable exploitation of this heap-based buffer overflow vulnerability.