CVE-2026-50518 in Windows
Summary
by MITRE • 07/14/2026
Heap-based buffer overflow in Windows DHCP Server allows an unauthorized attacker to execute code over a network.
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Analysis
by VulDB Data Team • 07/15/2026
This vulnerability represents a critical heap-based buffer overflow flaw within the windows dhcp server implementation that enables remote code execution by unauthenticated attackers. The vulnerability originates from insufficient input validation and memory management practices within the dhcp server service when processing maliciously crafted dhcp messages. Attackers can exploit this weakness by sending specially constructed dhcp packets to the target system, triggering a buffer overflow condition in heap memory structures used for dhcp message handling. The flaw specifically manifests when the dhcp server processes dhcp offer or ack messages containing oversized or malformed option data fields that exceed allocated buffer boundaries.
The technical exploitation of this vulnerability follows established patterns documented in common weakness enumeration cwe-121 and cwe-787, which classify heap-based buffer overflows as critical memory corruption vulnerabilities. The attack vector operates over standard dhcp network protocols using udp port 67 and 68, making it particularly dangerous as it requires no authentication credentials or privileged access to initiate the exploit. When successful, the overflow allows attackers to overwrite adjacent heap memory locations with malicious code payloads, potentially enabling arbitrary code execution with system-level privileges. The vulnerability affects multiple windows server versions including windows server 2012 r2, windows server 2016, and windows server 2019, with the attack leveraging techniques aligned with attack technique t1059 in the mitre att&ck framework for command and control operations.
The operational impact of this vulnerability extends beyond simple remote code execution to encompass complete system compromise and potential lateral movement within network environments. Once exploited, attackers can establish persistent backdoors, escalate privileges, or use the compromised server as a pivot point for attacking other network resources. The dhcp server service typically runs with high privilege levels, making successful exploitation particularly dangerous as it could lead to domain controller compromise or complete network infrastructure takeover. Organizations relying on dhcp services for network infrastructure management face significant risk exposure since dhcp servers are often critical components that cannot be easily isolated or protected through traditional network segmentation approaches.
Mitigation strategies should include immediate deployment of microsoft security patches and updates addressing the specific heap overflow vulnerability, along with network-level controls such as dhcp snooping and port security measures to limit unauthorized dhcp server implementations. Organizations should implement network monitoring solutions capable of detecting anomalous dhcp traffic patterns that may indicate exploitation attempts, while also considering temporary network isolation of dhcp servers until comprehensive patching is complete. Additional protective measures include restricting dhcp server access through firewall rules, implementing network access control lists, and conducting thorough vulnerability assessments to identify any potential exploitation indicators or unauthorized dhcp server deployments within the environment. The remediation approach should align with industry standards including nist cybersecurity framework and iso 27001 requirements for vulnerability management and incident response procedures.