What’s Vulnerable › Vulnerabilities

CVE-2026-18103: Dhcp-server: dhcp-server: persistent denial of service due to buffer overflow via omapi

• Severity: medium (CVSS 4.9 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-05 · updated 2026-08-06
• Weakness: CWE-120

Description

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.

Affected products

• Red Hat Enterprise Linux 6: all versions
• Red Hat Enterprise Linux 7: all versions
• Red Hat Enterprise Linux 8: all versions
• Red Hat Enterprise Linux 9: all versions

References

• https://access.redhat.com/security/cve/CVE-2026-18103
• https://bugzilla.redhat.com/show_bug.cgi?id=2508081

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