CVE-2026-49169 in Windows
Summary
by MITRE • 07/14/2026
Use after free in DNS Server allows an authorized attacker to execute code over a network.
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Analysis
by VulDB Data Team • 07/14/2026
This vulnerability represents a critical use-after-free condition within the dns server implementation that enables remote code execution when exploited by an authenticated attacker. The flaw occurs when the dns server processes certain network requests and subsequently frees memory resources that are then accessed again through malicious input, creating a scenario where an attacker can manipulate the freed memory to execute arbitrary code on the target system. Such vulnerabilities typically arise from improper memory management practices where objects are not properly validated before being accessed after deallocation, directly correlating to CWE-416 which addresses use-after-free errors in software implementations.
The operational impact of this vulnerability extends beyond simple remote code execution as it allows attackers with valid credentials or network access to escalate privileges and potentially compromise entire dns infrastructure. The attack vector leverages the dns server's processing of specific query formats or configuration parameters that trigger the memory corruption state, making it particularly dangerous in enterprise environments where dns servers serve as critical infrastructure components for network operations. This vulnerability can be exploited through standard network protocols and does not require specialized tools or conditions beyond valid authentication to the affected system.
Security professionals should consider implementing immediate mitigations including patching the dns server software to address the memory management flaw, deploying network segmentation to limit access to dns servers, and monitoring for suspicious dns query patterns that may indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1059 which covers command and scripting interpreter usage, as successful exploitation would likely involve executing malicious code through compromised dns services. Organizations should also review their access controls and implement least privilege principles to minimize the impact if an attacker successfully exploits this vulnerability.
Additional defensive measures include configuring intrusion detection systems to monitor for anomalous dns traffic patterns, implementing strict input validation on all dns server requests, and establishing regular security assessments of dns infrastructure components. The memory corruption nature of this flaw makes it particularly susceptible to exploitation through techniques such as heap spraying or return-oriented programming attacks, where attackers manipulate freed memory blocks to achieve code execution in the target process context. Regular updates and security hardening procedures should be prioritized to address similar vulnerabilities that may exist in other network services and components within the organization's infrastructure ecosystem.