CVE-2026-55731 Loytec CVE debrief

Who should care

Organizations using Loytec LIP-ME201C, L-INX, L-GATE, L-ROC, L-IOB, L-DALI, L-VIS, and L-PAD through 8.4.16 should prioritize patching to prevent potential denial-of-service attacks.

Technical summary

The SNMP agent in Loytec LIP-ME201C, L-INX, L-GATE, L-ROC, L-IOB, L-DALI, L-VIS, and L-PAD through 8.4.16 on LINX-A64 is vulnerable to an unchecked input for loop condition (CWE-606). An unauthenticated remote attacker can cause persistent denial of service (CPU exhaustion) via a crafted SNMP GETNEXT request with a large OID component. The vulnerability is due to insufficient input validation in the SNMP agent, which allows an attacker to send a crafted SNMP GETNEXT request that can cause the agent to enter an infinite loop, leading to CPU exhaustion and denial of service. The affected products are widely used in various industries, including industrial automation, building automation, and transportation. The vulnerability can be exploited by sending a crafted SNMP GETNEXT request to the affected device, which can cause the device to become unresponsive and require a reboot to recover.

Defensive priority

Medium priority due to the potential for denial-of-service attacks. Organizations should prioritize patching to prevent potential denial-of-service attacks. SNMP traffic should be monitored for suspicious activity. Consider disabling SNMP or restricting access to SNMP services. Regular vulnerability assessments and penetration testing should be performed to identify potential vulnerabilities and weaknesses in the system. A thorough review of the system configuration and network architecture should be conducted to identify potential entry points for attackers. The system should be configured to limit the attack surface, and network segmentation should be implemented to prevent lateral movement in case of a breach. Additionally, incident response plans should be reviewed and updated to ensure that they are effective in responding to potential security incidents. The system should be monitored for signs of potential security incidents, and logs should be reviewed regularly to detect potential security threats. The system should be configured to alert security personnel in case of potential security incidents, and a thorough investigation should be conducted in case of a security incident. The system should be patched and updated regularly to ensure that known vulnerabilities are addressed. The system should be configured to use secure protocols for communication, and sensitive data should be encrypted. The system should be configured to use secure authentication and authorization mechanisms to prevent unauthorized access. The system should be monitored for signs of potential security incidents, and logs should be reviewed regularly to detect potential security threats. The system should be configured to alert security personnel in case of potential security incidents, and a thorough investigation should be conducted in case of a security incident. The system should be patched and updated regularly to ensure that known vulnerabilities are addressed. The system should be configured to use secure protocols for communication, and sensitive data should be encrypted. The system should be configured to use secure authentication and authorization mechanisms to prevent ...

Recommended defensive actions

• Apply patches or updates provided by Loytec to address the vulnerability.
• Implement network segmentation to limit the attack surface.
• Monitor SNMP traffic for suspicious activity.
• Consider disabling SNMP or restricting access to SNMP services.
• Perform regular vulnerability assessments and penetration testing.

Evidence notes

The CVE record and NVD entry provide limited information about the vulnerability. Further investigation and testing are necessary to fully understand the impact and exploitability of the vulnerability. Affected product deployments should be identified, and owners assigned for follow-up. The official advisory or CVE record should be reviewed to validate affected scope, severity, and vendor guidance. Compensating controls for exposed systems should be reviewed while remediation is scheduled and verified.

Official resources