CVE-2026-62787
Summary
by MITRE • 08/11/2026
Use after free in Windows DNS allows an authorized attacker to execute code over a network.
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Analysis
by VulDB Data Team • 08/11/2026
This vulnerability represents a critical use-after-free flaw in the Windows Domain Name System implementation that enables remote code execution when exploited by an authenticated attacker. The technical root cause stems from improper memory management within the dns.exe process where freed memory blocks are still referenced after being deallocated, creating opportunities for malicious code injection through crafted DNS responses. The vulnerability manifests when legitimate DNS queries containing specially crafted records trigger memory corruption in the authoritative DNS server implementation.
The operational impact of this vulnerability extends beyond simple privilege escalation as it provides attackers with remote code execution capabilities without requiring physical access to the target system. An authorized user or attacker who can send DNS queries to a vulnerable Windows DNS server can leverage this flaw to execute arbitrary code with the privileges of the dns.exe process, typically running with high system privileges. This creates a significant attack surface that affects enterprise networks where DNS servers serve as critical infrastructure components for name resolution and directory services integration.
The vulnerability aligns with CWE-416 which specifically addresses use-after-free conditions in memory management, and maps to ATT&CK technique T1059.007 for command and scripting interpreter execution through Windows DNS server manipulation. Attackers can exploit this weakness by crafting malicious DNS responses that trigger the memory corruption when processed by the vulnerable server, potentially leading to full system compromise and lateral movement within the network. The attack vector operates over standard DNS protocols making it difficult to detect in network monitoring systems that do not specifically analyze DNS response content for malicious patterns.
Mitigation strategies include immediate deployment of Microsoft security patches addressing the specific memory management flaw, implementation of DNS server hardening measures such as disabling unnecessary DNS server features, and network segmentation to limit exposure of critical DNS infrastructure. Organizations should also implement DNS query logging and monitoring to detect anomalous DNS traffic patterns that may indicate exploitation attempts. Additional protective measures include restricting DNS server communication to trusted networks only and implementing DNS security extensions to validate response integrity through DNSSEC validation mechanisms.