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.
Published: 2026-08-04
Score: 4.9 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

Vendor Workaround

To mitigate this issue, secure OMAPI access by configuring TSIG key authentication to prevent unauthorized connections to the OMAPI port (7911). If the `dhcpd` service has already crashed due to this flaw, manually remove the problematic InfiniBand lease entry from `/var/lib/dhcpd/dhcpd.leases` and then restart the `dhcpd` service. Restarting the `dhcpd` service may temporarily interrupt DHCP services for clients.

Tracking

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Advisories

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History

Wed, 05 Aug 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 05 Aug 2026 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Low


Wed, 05 Aug 2026 10:45:00 +0000

Type Values Removed Values Added
First Time appeared Dhcp-server
Dhcp-server dhcp-server
Vendors & Products Dhcp-server
Dhcp-server dhcp-server

Tue, 04 Aug 2026 23:30:00 +0000

Type Values Removed Values Added
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.
Title Dhcp-server: dhcp-server: persistent denial of service due to buffer overflow via omapi
First Time appeared Redhat
Redhat enterprise Linux
Weaknesses CWE-120
CPEs cpe:/o:redhat:enterprise_linux:6
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
References
Metrics cvssV3_1

{'score': 4.9, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H'}


Subscriptions

Dhcp-server Dhcp-server
Redhat Enterprise Linux
cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-08-05T13:58:53.130Z

Reserved: 2026-07-28T17:35:42.520Z

Link: CVE-2026-18103

cve-icon Vulnrichment

Updated: 2026-08-05T13:58:49.665Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-08-05T00:16:59.110

Modified: 2026-08-06T15:37:22.093

Link: CVE-2026-18103

cve-icon Redhat

Severity : Low

Publid Date: 2026-07-28T17:35:55Z

Links: CVE-2026-18103 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-05T10:18:51Z

Weaknesses