CVE-2026-18103
Dhcp-server: dhcp-server: persistent denial of service due to buffer overflow via omapi
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.
INFO
Published Date :
Aug. 5, 2026, 12:16 a.m.
Last Modified :
Aug. 5, 2026, 12:16 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-18103
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 53f830b8-0a3f-465b-8143-3b8a9948e749 | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE |
Solution
- Update dhcp-server to the latest version.
- Secure OMAPI port with TSIG key authentication.
- Restrict network access to the OMAPI port.
- Restart the dhcpd service manually if it crashes.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-18103.
| URL | Resource |
|---|---|
| https://access.redhat.com/security/cve/CVE-2026-18103 | |
| https://bugzilla.redhat.com/show_bug.cgi?id=2508081 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-18103 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-18103
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-18103 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-18103 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Aug. 05, 2026
Action Type Old Value New Value Added Affected [{'cpes': ['cpe:/o:redhat:enterprise_linux:6'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 6', 'packageName': 'dhcp', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:7'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 7', 'packageName': 'dhcp', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:8'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8', 'packageName': 'dhcp', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:9'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9', 'packageName': 'dhcp', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}] 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. Added CVSS V3.1 AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-120 Added Reference https://access.redhat.com/security/cve/CVE-2026-18103 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2508081