CVE-2026-62719 in Windows
Summary
by MITRE • 08/11/2026
Heap-based buffer overflow in Windows Message Queuing allows an authorized attacker to elevate privileges locally.
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Analysis
by VulDB Data Team • 08/11/2026
A heap-based buffer overflow vulnerability exists within the Windows Message Queuing component that enables a locally authenticated attacker to escalate their privileges from standard user level to system level. This vulnerability stems from inadequate bounds checking during heap memory allocation and manipulation processes within the messaging subsystem. The flaw occurs when the system processes malformed or oversized message data structures that exceed predetermined buffer limits, causing adjacent heap memory regions to be overwritten. Such overflows can corrupt critical heap metadata structures including heap headers, free list pointers, and chunk management information, ultimately leading to arbitrary code execution capabilities. The vulnerability is classified under CWE-121 Heap-based Buffer Overflow which specifically addresses buffer overflows occurring in heap memory regions where attackers can manipulate heap allocation patterns to achieve privilege escalation.
The operational impact of this vulnerability extends beyond simple local privilege escalation as it provides attackers with a reliable method to gain SYSTEM level access on compromised Windows systems. Once successfully exploited, the attacker can execute malicious code with the highest system privileges, potentially enabling complete system compromise, data exfiltration, or establishment of persistent backdoors. The attack vector requires only local authentication since the vulnerability exists within a component that operates at the kernel level and is accessible to authenticated users. This makes it particularly dangerous in environments where multiple users share systems or where credential compromise occurs through other attack vectors such as phishing or exploitation of network services.
Security professionals should implement immediate mitigations including applying Microsoft security patches, enabling heap-based memory protection mechanisms like Data Execution Prevention, and implementing strict access controls for message queue services. The vulnerability aligns with ATT&CK technique T1068 which covers 'Exploitation for Privilege Escalation' and specifically addresses the path to SYSTEM level access through kernel-mode exploitation. Organizations should also consider deploying heap spraying techniques and runtime monitoring to detect potential exploitation attempts targeting heap-based vulnerabilities. Additional defensive measures include restricting user permissions, implementing application whitelisting policies, and conducting regular security assessments of message queue configurations to identify misconfigurations that could facilitate exploitation. The vulnerability demonstrates the critical importance of proper memory management practices in kernel-level components and reinforces the necessity of comprehensive security testing for system services that handle user-supplied data.