CVE-2026-97826 in Windows
Summary
by MITRE • 10/15/2026
Out-of-bounds read in DNS Server allows an authorized attacker to disclose information over a network.
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Analysis
by VulDB Data Team • 10/15/2026
The vulnerability described constitutes a critical security flaw within the Domain Name System (DNS) server infrastructure, specifically manifesting as an out-of-bounds read condition. This type of memory safety error occurs when the software attempts to access data at a memory location that is outside the boundaries of the intended buffer or array structure. In the context of DNS servers, which are fundamental components of internet connectivity responsible for resolving domain names into IP addresses, such flaws can have severe implications for system stability and information confidentiality. The specific nature of this vulnerability allows an attacker who has already gained authorized access to exploit the memory mismanagement issue, leading to the disclosure of sensitive internal data that should remain isolated from external or unauthorized observation.
From a technical perspective, out-of-bounds reads are often categorized under Common Weakness Enumeration (CWE) identifiers such as CWE-125, which describes an out-of-bounds read vulnerability where software reads past the end of a buffer. This flaw typically arises due to insufficient validation of input parameters or incorrect calculation of array indices during packet processing routines within the DNS server application logic. When a specially crafted DNS query is processed by the vulnerable component, the erroneous memory access may retrieve data from adjacent memory regions that contain sensitive information such as internal network configurations, cached records, cryptographic keys, or other process-specific data structures. The attacker leverages this unauthorized read operation to exfiltrate this confidential information over the network, effectively bypassing standard security controls because the action is performed by an authenticated user account.
The operational impact of this vulnerability extends beyond simple data leakage. By disclosing internal system details, an attacker can gain deeper insights into the target environment's architecture and security posture. This intelligence gathering phase enables further exploitation attempts, such as crafting more precise attacks against other services running on the same host or within the local network segment. Furthermore, depending on the specific implementation of the DNS server, repeated triggering of this vulnerability could potentially lead to service instability if the memory corruption affects critical control structures, although the primary risk highlighted here is information disclosure rather than denial of service. The presence of an authorization requirement indicates that while remote unauthenticated exploitation is not possible, insider threats or compromised legitimate accounts pose a significant threat vector for data exfiltration through this channel.
To mitigate the risks associated with this vulnerability, organizations must prioritize immediate patching by applying vendor-released updates that address the memory management logic errors within the DNS server software. Access control mechanisms should be rigorously reviewed to ensure that only essential personnel have administrative or high-privilege access to DNS infrastructure components, adhering to the principle of least privilege. Network segmentation strategies can also help limit the blast radius by isolating critical name resolution services from general user networks and restricting inter-service communication protocols where possible. Additionally, implementing robust logging and monitoring solutions will aid in detecting anomalous query patterns or unusual memory usage behaviors that may indicate exploitation attempts. Regular security assessments and code reviews focusing on input validation and buffer boundary checks are essential preventive measures to eliminate such weaknesses at the development stage before deployment into production environments.