CVE-2026-62717 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
This vulnerability represents a critical heap-based buffer overflow within the Windows Message Queuing (MSMQ) component that enables local privilege escalation for authenticated attackers. The flaw exists in how the system handles memory allocation and data processing within the messaging subsystem, specifically when processing malformed or oversized message data structures. The vulnerability stems from inadequate bounds checking during heap memory operations, allowing an attacker to overwrite adjacent memory regions with controlled data. This particular issue manifests when MSMQ processes messages that exceed expected buffer sizes, causing the heap allocator to place subsequent data beyond the allocated memory boundaries. The technical implementation involves improper validation of message content length parameters and insufficient input sanitization before memory allocation occurs.
The operational impact of this vulnerability extends beyond simple privilege escalation as it provides attackers with elevated system privileges that can be leveraged for further compromise within the Windows environment. An attacker must first establish a local presence on the target system, typically through legitimate user credentials or compromised accounts, to exploit this weakness. Once successfully exploited, the buffer overflow enables execution of arbitrary code with SYSTEM-level privileges, effectively bypassing standard user access controls and security boundaries. The vulnerability affects systems running various Windows versions including server and desktop editions where MSMQ is installed, making it particularly dangerous in enterprise environments where message queuing services are commonly deployed for inter-application communication.
Security professionals should implement immediate mitigations including applying the latest microsoft security patches that address this heap overflow condition through proper bounds checking and memory management routines. Network segmentation and access control measures can help limit potential exploitation by restricting local access to systems running MSMQ services. Monitoring for unusual message processing patterns or memory allocation anomalies in system logs may provide early detection of attempted exploitation. The vulnerability aligns with CWE-121 heap-based buffer overflow classification and maps to attack techniques within the MITRE ATT&CK framework under privilege escalation and execution domains. Organizations should also consider disabling MSMQ services on systems where they are not required, implementing application whitelisting policies, and conducting regular security assessments to identify similar memory corruption vulnerabilities that could be exploited for similar outcomes.