CVE-2026-18103: Red Hat Enterprise Linux 6 · Classic Buffer Overflow
Affects Red Hat Enterprise Linux 6Source CVE Database V5
Not known to be exploited · CVSS 4.9 Medium.
Data as of 2 Nov 2026, 22:58 UTC
- 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 2 Nov 2026.
What to do
Affected software
| Product | 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– |
| Red Hat Enterprise Linux 9dhcp | Affected– | Fixed in– |
AI-suggested
To mitigate this vulnerability, configure TSIG key authentication on the OMAPI port (7911) to prevent unauthorized access. If the dhcpd service has crashed due to this flaw, manually remove the problematic InfiniBand lease entry from /var/lib/dhcpd/dhcpd.leases and then restart the dhcpd service. Note that restarting the service may temporarily interrupt DHCP services for clients.
Description
A buffer overflow vulnerability exists in the dhcp-server component of Red Hat Enterprise Linux 6. An attacker with network access to the OMAPI port (7911), if not secured with TSIG key authentication, can send a specially crafted lease creation request containing an overly long InfiniBand MAC address. This triggers a buffer overflow in the print_hw_addr() function, causing the dhcpd service to crash and preventing it from restarting without manual intervention, resulting in a persistent denial of service (DoS).