CVE-2026-62814 in Windows
Summary
by MITRE • 08/11/2026
Integer underflow (wrap or wraparound) in Windows DHCP Server allows an unauthorized attacker to disclose information over an adjacent network.
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Analysis
by VulDB Data Team • 08/11/2026
This vulnerability represents a critical integer underflow condition within the windows dhcp server implementation that enables unauthorized remote attackers to exploit network proximity to gather sensitive information. The flaw occurs when the dhcp server processes certain malformed packets or requests where integer values wrap around to negative numbers, creating unexpected behavior in memory management and data handling routines. This particular weakness falls under the common weakness enumeration category CWE-190 which specifically addresses integer overflow and underflow conditions that can lead to unpredictable system states and potential information disclosure.
The technical exploitation requires an attacker to be positioned on the same network segment as the target dhcp server, leveraging what is known as an adjacent network attack vector. When malformed dhcp packets are sent to the vulnerable server, the integer underflow causes the server to process memory regions incorrectly, potentially leading to heap-based buffer overflows or information leaks from adjacent memory locations. The vulnerability essentially allows attackers to read memory contents that should remain protected, including potentially sensitive configuration data, user credentials, or system state information that could be used for further exploitation attempts.
From an operational impact perspective, this vulnerability compromises the confidentiality and integrity of network infrastructure by enabling information disclosure without requiring authentication or complex attack chains. The attack can be executed with minimal resources and technical expertise, making it particularly dangerous in enterprise environments where dhcp servers are critical components managing network access and configuration distribution. Network administrators may not immediately detect such attacks as they appear to be normal dhcp traffic patterns, creating a stealthy threat vector that could remain undetected for extended periods.
The exploitation of this vulnerability aligns with several tactics described in the attack technique framework including initial access through adjacent network compromise and privilege escalation via information gathering. Organizations should implement immediate mitigations including network segmentation to isolate dhcp servers, deployment of intrusion detection systems to monitor for unusual dhcp traffic patterns, and application of microsoft security patches addressing the specific integer underflow condition. Additionally, network monitoring solutions should be configured to detect anomalous dhcp packet structures that may indicate exploitation attempts, while regular security assessments should verify dhcp server configurations and ensure proper access controls are in place to limit exposure to unauthorized network entities.
The underlying issue demonstrates how seemingly simple programming errors can create significant security implications in widely deployed network infrastructure components. This vulnerability highlights the importance of proper input validation and integer handling in server applications, particularly those operating in critical network roles where information disclosure can lead to broader system compromise. Organizations should prioritize patch management programs that address such fundamental software flaws while implementing defensive measures such as dhcp snooping and dynamic access control policies to limit potential attack surface exposure.