CVE-2026-3838 in Unraid
Summary
by MITRE • 03/16/2026
Unraid Update Request Path Traversal Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Unraid. Authentication is required to exploit this vulnerability.
The specific flaw exists within the update.php file. The issue results from the lack of proper validation of a user-supplied path prior to using it in file operations. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-28951.
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Analysis
by VulDB Data Team • 03/25/2026
The CVE-2026-3838 vulnerability represents a critical path traversal flaw in Unraid's update.php component that enables remote code execution with root privileges. This vulnerability specifically targets the update request handling mechanism within the Unraid operating system, which is widely used for home and small business server deployments. The flaw stems from inadequate input validation where user-supplied paths are directly processed without proper sanitization or verification, creating an exploitable condition that allows attackers to manipulate file system operations. The vulnerability requires authentication to exploit, meaning an attacker must first establish valid credentials before attempting the attack vector, though this does not mitigate the severity of the potential impact.
The technical implementation of this vulnerability resides in the update.php file where the application fails to properly validate or sanitize user-provided path parameters before utilizing them in file operations. This lack of proper input validation creates a classic path traversal condition that allows an authenticated attacker to manipulate the update process and potentially execute arbitrary code with the highest system privileges. The vulnerability operates at the file system level where legitimate update functionality can be subverted to perform unauthorized file operations, including reading, writing, or executing files outside of the intended scope. The root context execution privilege escalation occurs because the update process runs with elevated permissions, making this a particularly dangerous vulnerability for systems where Unraid serves as the primary operating platform.
The operational impact of this vulnerability extends beyond simple code execution to encompass complete system compromise and potential data exfiltration. An authenticated attacker could leverage this vulnerability to install malicious software, modify system files, establish persistence mechanisms, or access sensitive data stored on the affected system. The implications are particularly severe for Unraid deployments that serve as central storage solutions or network infrastructure components, as these systems often contain critical business or personal data. The vulnerability's ability to execute code in the root context means that successful exploitation could result in complete system takeover, allowing attackers to maintain persistent access and potentially use the compromised system as a launching point for further attacks within the network environment.
Mitigation strategies for CVE-2026-3838 should focus on immediate patch application from Unraid vendor releases, followed by comprehensive network monitoring to detect potential exploitation attempts. Organizations should implement strict access controls and credential management practices to minimize the risk of unauthorized authentication. The vulnerability aligns with CWE-22 Path Traversal and CWE-74 Command Injection categories, and maps to ATT&CK techniques involving privilege escalation and execution through valid accounts. Security teams should conduct thorough vulnerability assessments of all Unraid installations and consider implementing network segmentation to limit the potential impact of successful exploitation. Additionally, regular security updates and patch management processes should be strengthened to ensure timely remediation of similar vulnerabilities in the future.