CVE-2026-52190: UTT nv518G Buffer Overflow Remote Denial of Service

Technical summary

CVE-2026-52190 is a stack-based buffer overflow (CWE-121) in the gohead/sub_448384 function of the UTT nv518G device. The vulnerability exists in firmware version 3.2.7-210919-161313 and is reachable over the network without authentication. The flaw permits an unauthenticated remote attacker to overflow a stack buffer, resulting in denial of service through process crash or hang. Buffer overflows in network-facing components are particularly concerning because they may enable code execution under certain circumstances, depending on memory protections and exploitation feasibility.

Business impact

Affected UTT nv518G devices are likely small form-factor networking or security appliances commonly deployed at branch offices, retail locations, or small business perimeters. Exploitation causes immediate service interruption—the targeted device becomes unavailable until manual restart. For organizations relying on these devices for connectivity, access control, or monitoring, an attack disrupts business continuity. The lack of authentication requirements means an attacker anywhere on the internet can trigger the denial of service, creating potential for coordinated attacks across a customer base.

Affected systems

UTT nv518G device running firmware version 3.2.7-210919-161313. Organizations should verify whether they operate this specific model and firmware version. No additional variants or affected product versions are documented in the available source data; verify with UTT for any other potentially vulnerable firmware releases or related product lines.

Exploitability

The vulnerability is remotely exploitable without authentication, authentication burden, or user interaction—conditions that maximize accessibility. The attack vector is network-based, making it reachable from the internet if the device is internet-connected or accessible from untrusted networks. The attack complexity is low, indicating the vulnerability is straightforward to exploit. No public exploit code is currently confirmed, and the vulnerability is not yet listed on the CISA Known Exploited Vulnerabilities catalog, suggesting limited real-world weaponization to date. However, the technical straightforwardness of buffer overflow exploitation means public tooling or proof-of-concept code could emerge rapidly.

Remediation

UTT has not yet released a patched firmware version documented in the vulnerability record. Organizations should immediately contact UTT support to inquire about firmware updates addressing this flaw, or request an estimated timeline for a security release. Interim mitigations include network segmentation to restrict access to the gohead service (typically port 80 or 443) to trusted sources only, disabling the web interface if not required for operations, or disconnecting affected devices from untrusted networks pending a patch.

Patch guidance

Verify the current firmware version on your UTT nv518G device by accessing the administrative interface (check device documentation for default credential warnings). Compare against the vulnerable version 3.2.7-210919-161313. Contact UTT technical support or check their security advisories for available firmware updates. When a patch is released, test it in a non-production environment first to ensure compatibility with your network configuration. Apply the update during a maintenance window to minimize disruption.

Detection guidance

Monitor network traffic to UTT nv518G devices for unusual requests to the gohead component. Implement network-based intrusion detection rules to flag oversized or malformed HTTP requests targeting the vulnerable service. Monitor device logs and system health for unexplained reboots or service restarts, which may indicate exploitation attempts. If your organization has endpoint detection and response (EDR) or network monitoring tools, baseline the normal behavior of these devices and alert on anomalies. Conduct periodic firmware audits to confirm devices remain on supported and patched versions.

Why prioritize this

The CVSS 3.1 score of 7.5 (HIGH) reflects the combination of network accessibility, lack of authentication barriers, and availability impact. While the current known impact is denial of service rather than confidentiality or integrity breach, the underlying buffer overflow vulnerability represents a structural weakness that could be more severely exploited if memory protections are weak or bypass techniques are discovered. Organizations operating these devices should prioritize patching to eliminate the flaw rather than relying solely on network controls, which can be circumvented if the device is internet-facing.

Risk score, explained

The CVSS vector (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) indicates: Network Attack Vector (maximum reach), Low Attack Complexity (trivial to exploit), No Privileges Required (unauthenticated), No User Interaction needed, and High impact to Availability. The score of 7.5 reflects these factors without confidentiality or integrity damage currently documented. The absence of public exploitation evidence and KEV listing moderates urgency slightly, but the unauthenticated network nature and buffer overflow class warrant swift remediation.

Frequently asked questions