CVE-2026-19983 in A1300
Summary
by MITRE • 08/17/2026
A vulnerability was detected in GL.iNet A1300, AX1800, AXT1800, MT2500, MT3000, MT6000, X3000 and XE3000 4.8.x. This issue affects some unknown processing of the file /usr/bin/gl_nas_sys of the component NAS Command Service. The manipulation results in os command injection. The attack may be launched remotely. Upgrading to version 4.9.0 is capable of addressing this issue. It is suggested to upgrade the affected component. The vendor explains: "After our investigation, we have confirmed that the vulnerability described (...) does indeed exist."
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Analysis
by VulDB Data Team • 08/17/2026
The GL.iNet router series including models A1300, AX1800, AXT1800, MT2500, MT3000, MT6000, X3000, and XE3000 running firmware version 4.8.x are affected by a critical remote code execution vulnerability within the NAS Command Service component. This security flaw is rooted in improper input validation and sanitization mechanisms present in the binary executable located at /usr/bin/gl_nas_sys. The core technical deficiency involves an operating system command injection (OSCI) weakness, which allows an attacker to inject arbitrary shell commands into the application's execution flow by manipulating specific inputs passed to this service. This type of flaw is formally categorized under CWE-78 in the Common Weakness Enumeration standard, representing a failure to neutralize special elements used in OS commands before they are executed.
The operational impact of this vulnerability is severe due to its remote exploitability and the privileged nature of the affected component. Because the NAS Command Service typically runs with elevated privileges on embedded Linux systems, successful exploitation grants an attacker full control over the underlying operating system. This can lead to complete compromise of the router's integrity, confidentiality, and availability. An adversary could use this access to pivot into internal network segments, exfiltrate sensitive data stored on connected NAS devices, install persistent backdoors such as cryptominers or botnet clients, or disrupt network connectivity for all users relying on these routers. The ability to execute commands remotely means that physical access is not required, significantly expanding the attack surface and increasing the risk of widespread automated exploitation by malicious actors scanning for vulnerable firmware versions.
From a threat intelligence perspective, this vulnerability aligns with ATT&CK techniques related to Command and Scripting Interpreter abuse, specifically T1059 which covers execution via various scripting languages or shell commands. The remote nature of the attack also correlates with initial access vectors where attackers leverage exposed services on internet-facing devices to gain an foothold within a network perimeter. Given that GL.iNet routers are often deployed in home and small business environments without robust segmentation, this vulnerability poses a disproportionate risk compared to enterprise-grade equipment which might have additional layers of security controls or restricted management interfaces.
To mitigate the risks associated with CVE details pertaining to these devices, immediate action is required by system administrators and end-users. The vendor has confirmed the existence of the flaw and released firmware version 4.9.0 which addresses the input validation issues within the gl_nas_sys binary. Upgrading to this patched version is the primary recommended remediation strategy. Organizations should prioritize updating all affected devices in their inventory as soon as possible. In scenarios where immediate patching is not feasible, temporary mitigations may include restricting network access to the management interfaces of these routers using firewall rules or VLAN segmentation to limit exposure to untrusted networks. Additionally, monitoring for unusual outbound traffic patterns from these devices can help detect potential exploitation attempts before significant damage occurs. Regular firmware maintenance and adherence to vendor security advisories are essential practices for maintaining the security posture of IoT infrastructure.