CVE-2026-95394 in Network Monitor
Summary
by MITRE • 09/29/2026
Microsoft Network Monitor file parser large loop in 4.6.0 to 4.6.8 and 4.4.0 to 4.4.18 allows denial of service
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Analysis
by VulDB Data Team • 09/29/2026
The vulnerability identified involves a critical flaw within the file parsing logic of Microsoft Network Monitor, specifically affecting versions ranging from 4.4.0 through 4.4.18 and 4.6.0 through 4.6.8. This software is widely utilized by network administrators for capturing and analyzing network traffic data to troubleshoot connectivity issues and monitor performance metrics. The core of the vulnerability lies in an improper handling of loop conditions during the parsing process when processing specific, potentially malformed or crafted input files. When a user opens a specially constructed file designed to exploit this logic error, the application enters an infinite or excessively long execution loop rather than terminating gracefully or reporting an invalid format error. This behavior is characteristic of inefficient resource management and lack of proper bounds checking in legacy parsing routines that have not been adequately hardened against adversarial inputs over time.
From a technical perspective, this flaw represents a classic denial-of-service scenario driven by computational exhaustion. The application consumes significant central processing unit cycles as it attempts to process the malformed data structure indefinitely. This uncontrolled loop prevents the software from performing any other tasks and effectively freezes the user interface, rendering the tool unusable until the process is manually terminated via task manager or system restart mechanisms. In environments where Microsoft Network Monitor is used for real-time monitoring or incident response, such a freeze can lead to significant operational disruptions. Administrators may lose visibility into network traffic at critical moments, hindering their ability to detect ongoing attacks or diagnose complex networking problems that require immediate attention and continuous data capture capabilities.
The impact of this vulnerability extends beyond simple application unresponsiveness. In shared computing environments or server-based deployments where multiple users might access the tool remotely or through automated scripts, a single malicious file could potentially degrade system performance for other processes running on the same host if resource limits are not strictly enforced by the operating system. While the primary impact is localized to denial of service rather than remote code execution or data exfiltration, the reliability of network diagnostic tools is paramount in enterprise IT infrastructure. The inability to reliably parse standard capture files due to this bug undermines trust in the toolset and forces administrators to rely on alternative methods that may be less efficient or more difficult to deploy quickly during an emergency situation.
This vulnerability aligns with Common Weakness Enumeration category CWE-835, which describes a loop involving unnecessary iterations, often resulting from missing bounds checks or incorrect termination conditions. It also maps to the MITRE ATT&CK framework under techniques associated with resource exhaustion and denial of service attacks, specifically those that target application availability rather than confidentiality or integrity. The existence of such flaws in older versions highlights the importance of maintaining up-to-date software suites within an organization's security posture. Legacy tools often contain code paths that were not designed with modern adversarial tactics in mind, making them susceptible to simple logic-based exploits that require minimal sophistication from an attacker but yield high availability impact for defenders relying on these utilities.
To mitigate this risk, organizations must ensure that all instances of Microsoft Network Monitor are updated to versions beyond 4.6.8 and 4.4.18 where the underlying parsing engine has been corrected to handle malformed inputs gracefully without entering infinite loops. If updating is not immediately feasible due to compatibility constraints with legacy systems or specific workflow dependencies, strict access controls should be implemented to prevent untrusted users from opening arbitrary capture files within the application. Additionally, deploying network monitoring solutions that incorporate sandboxing mechanisms can isolate potential crashes and protect the host operating system from resource exhaustion attacks. Regular vulnerability assessments focusing on administrative tools are essential to identify such legacy weaknesses before they can be leveraged by malicious actors seeking to disrupt operational continuity or distract security teams during broader attack campaigns.