CVE-2026-18103: dhcp-server · Buffer Overflow
Source GCVE Database
Not known to be exploited · CVSS 4.9 Medium : update Red Hat Enterprise Linux 9 when convenient.
Data as of 10 Nov 2026, 23:24 UTC
Thin evidence
One scorer or none| CNA (redhat) | CVSS 3.1 | 4.9 |
|---|
- EPSS
- 0.7% chance of exploitation in 30 days – higher than 53% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 4 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 10 Nov 2026.
What to do
Patches and advisories
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Red Hat Enterprise Linux 9dhcp | Affected– | Fixed in– |
| Red Hat Enterprise Linux 6dhcp | Affected– | Fixed in– |
| Red Hat Enterprise Linux 7dhcp | Affected– | Fixed in– |
| Red Hat Enterprise Linux 8dhcp | Affected– | Fixed in– |
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.