CVE-2026-50485 in Windows
Summary
by MITRE • 07/14/2026
Buffer over-read in Windows Hyper-V allows an authorized attacker to deny service over an adjacent network.
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Analysis
by VulDB Data Team • 07/14/2026
This vulnerability represents a critical buffer over-read condition within the Windows Hyper-V hypervisor implementation that enables authenticated attackers to execute denial of service attacks against Hyper-V hosts and virtual machines. The flaw occurs when the hypervisor processes certain network packets or data structures without proper bounds checking, allowing malicious input to overflow allocated memory buffers and potentially cause system instability or complete service disruption. The vulnerability specifically manifests in the Hyper-V networking components where adjacent network traffic can trigger the over-read condition through crafted packet sequences or malformed network protocols. This issue affects Windows Server versions that include Hyper-V functionality and presents a significant operational risk as it requires minimal privileges to exploit, making it particularly dangerous in environments where network access is not strictly controlled.
The technical nature of this vulnerability aligns with CWE-125, which describes out-of-bounds read conditions in software implementations. The flaw enables an attacker with network access to the Hyper-V host or virtual machines to send specially crafted packets that cause the hypervisor to read memory beyond allocated buffer boundaries. This over-read can result in system crashes, unexpected behavior, or complete denial of service for virtualized workloads running on the affected Hyper-V hosts. The operational impact extends beyond simple service interruption as it affects the entire virtualization infrastructure, potentially compromising multiple virtual machines and their hosted applications simultaneously.
From an adversarial perspective, this vulnerability maps directly to ATT&CK technique T1499.004 which covers network denial of service attacks. The adjacent network requirement means attackers can leverage local network access or compromised systems within the same broadcast domain to execute the attack. This makes the vulnerability particularly concerning in enterprise environments where network segmentation may not be comprehensive, as a single compromised endpoint could potentially affect multiple Hyper-V hosts and their virtualized workloads. The attack vector requires minimal skill level as it exploits existing protocol processing code paths rather than requiring complex exploitation techniques or zero-day vulnerabilities.
Organizations should implement immediate mitigations including applying Microsoft security updates, implementing network segmentation to limit adjacent network access to Hyper-V hosts, and monitoring for unusual network traffic patterns that could indicate exploitation attempts. The vulnerability also highlights the importance of maintaining current security patches across virtualization infrastructure, as unpatched systems present significant attack surfaces for sophisticated adversaries. Network administrators should consider implementing firewall rules to restrict unnecessary network access to Hyper-V host systems while ensuring that legitimate management traffic can still flow through the network infrastructure. Additionally, organizations should conduct vulnerability assessments to identify all systems running Hyper-V and evaluate their exposure to this type of denial of service condition.
The broader implications extend to cloud service providers and enterprises that rely heavily on virtualization technologies, as this vulnerability could potentially be exploited in multi-tenant environments to disrupt services for multiple customers simultaneously. Regular security assessments should include testing of virtualization components to identify similar buffer over-read conditions that could lead to more severe exploitation scenarios. The vulnerability also reinforces the need for comprehensive incident response procedures that account for virtualization-specific attack vectors and their potential cascading effects across multiple systems within a virtualized infrastructure.