CVE-2026-102226 in Dynamics Business Central
Summary
by MITRE • 10/13/2026
Improper limitation of a pathname to a restricted directory ('path traversal') in Dynamics Business Central allows an authorized attacker to elevate privileges over a network.
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Analysis
by VulDB Data Team • 10/14/2026
The vulnerability identified as improper limitation of a pathname to a restricted directory, commonly referred to as path traversal or directory traversal, represents a critical security flaw within Microsoft Dynamics Business Central. This class of vulnerabilities occurs when software constructs file paths from user-supplied input without sufficiently neutralizing special elements that can cause those paths to resolve outside the intended directory structure. In the context of Dynamics Business Central, this architectural weakness allows an attacker who has already obtained valid authentication credentials for a low-privileged account to manipulate file system operations. By injecting specific sequences such as dot-dot-slash (../) or their URL-encoded equivalents into input fields that are processed by backend services handling file I/O operations, the attacker can redirect read and write actions to arbitrary locations on the server's operating system. This capability fundamentally undermines the principle of least privilege and the isolation boundaries established between application components and the underlying host environment.
From a technical perspective, this flaw stems from insufficient validation or sanitization of user-controlled data before it is concatenated into file path strings. When Dynamics Business Central processes requests involving file uploads, downloads, or configuration changes, it may fail to properly canonicalize these paths or verify that they remain within the designated application root directory. This oversight enables an authorized attacker to traverse up through parent directories and access sensitive system files, configuration data, or other applications stored on the same server. The ability to read arbitrary files can lead to the exposure of database connection strings, encryption keys, or internal network topology details. Conversely, if write permissions are misconfigured in conjunction with this traversal flaw, an attacker could potentially overwrite critical application binaries or inject malicious scripts into web-accessible directories, thereby escalating from a simple path traversal issue to full remote code execution capabilities on the compromised host.
The operational impact of this vulnerability is severe due to its potential for privilege escalation over a network. Although the initial access requires valid credentials, which might suggest it is not an unauthenticated attack vector, the ability to elevate privileges means that even standard user accounts can be leveraged by malicious insiders or external attackers who have compromised legitimate credentials through phishing or credential stuffing attacks. Once inside, the attacker gains significant leverage over the entire Microsoft Dynamics environment and potentially the broader network infrastructure hosting the application server. This can result in unauthorized access to sensitive business data, including financial records, customer information, and proprietary intellectual property stored within the ERP system. Furthermore, if the Business Central instance is integrated with other enterprise systems via APIs or shared storage, the compromise of this single component could serve as a pivot point for lateral movement across the corporate network, leading to widespread data breaches and operational disruption.
To mitigate these risks, organizations must implement defense-in-depth strategies that address both application-level flaws and infrastructure configurations. Developers should ensure that all file path inputs are strictly validated against an allowlist of permitted characters and directories, utilizing canonicalization functions provided by the underlying operating system or framework to resolve paths before access checks occur. Input validation should reject any input containing directory traversal sequences regardless of encoding attempts. Additionally, running Dynamics Business Central services under least-privilege accounts with restricted file system permissions can limit the damage even if a path traversal is exploited. Network segmentation and strict firewall rules restricting inbound traffic to only necessary ports further reduce the attack surface. Regular security assessments, including static code analysis focused on input handling and dynamic penetration testing targeting authentication flows, are essential for identifying such vulnerabilities early in the development lifecycle or during routine maintenance windows before they can be weaponized by adversaries.