CVE-2026-18103

MediumCVSS 4.9

Published: 05/08/2026(UTC)Updated: 06/08/2026(UTC)Translated: 05/08/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.40%

33th percentile - higher than 33% of all known CVEs

Summary

A flaw was found in dhcp-server. A remote attacker with network access to the OMAPI port, especially if not secured with TSIG, can send a specially crafted lease creation request with an overly long InfiniBand MAC address, triggering a buffer overflow in print_hw_addr(). Successful exploitation leads to persistent denial of service, crashing dhcpd and preventing restart without manual intervention.

Risk Assessment

The attack can completely disable the DHCP service, preventing clients from obtaining IP addresses and causing network outages. Manual administrator intervention is required, extending downtime.

Recommendation

Secure the OMAPI port with TSIG keys and restrict network access. Update dhcp-server to a patched version.

Other vulnerabilities in dhcp-server

CVE-2024-38236High
Denial of Service vulnerability in DHCP Server service. An attacker could cause the DHCP service to fail.

Original NVD description (English source)

A flaw was found in dhcp-server. A remote attacker with network access to the OMAPI (Open Management Application Programming Interface) port, especially if not secured with TSIG (Transaction Signature) key authentication, could send a specially crafted lease creation request. This request, containing an overly long InfiniBand MAC address, triggers a buffer overflow in the `print_hw_addr()` function. Successful exploitation leads to a persistent denial of service (DoS), causing the `dhcpd` service to crash and preventing it from restarting without manual intervention.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS