CVE-2026-18103

MEDIUM

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

Title source: cna
STIX 2.1

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.

References (2)

Core 2
Core References
Vdb Entry, X_Refsource_Redhat vdb-entry x_refsource_redhat
https://access.redhat.com/security/cve/CVE-2026-18103
Issue Tracking, X_Refsource_Redhat issue-tracking x_refsource_redhat
RHBZ#2508081
https://bugzilla.redhat.com/show_bug.cgi?id=2508081

Scores

CVSS v3 4.9
EPSS 0.0040
EPSS Percentile 33.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-120
Status published
Products (4)
Red Hat/Red Hat Enterprise Linux 6
Red Hat/Red Hat Enterprise Linux 7
Red Hat/Red Hat Enterprise Linux 8
Red Hat/Red Hat Enterprise Linux 9
Published Aug 05, 2026
Tracked Since Aug 05, 2026