CVE-2026-18103
MEDIUM 4.9A 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.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.4%chance of exploitation in 30 days · 34th percentile
Impact if exploited
4.9CVSS 3.1 · MEDIUM
- ConfidentialityNone
- IntegrityNone
- AvailabilityHigh
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ⚠Privileges: Requires an admin / high-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-18103/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-18103/poc.json
Affected
Vendors Red Hat
Products Red Hat Enterprise Linux 6 Red Hat Enterprise Linux 7 Red Hat Enterprise Linux 8 Red Hat Enterprise Linux 9
Weakness (CWE)
- CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
All CVSS metrics
- MEDIUM 4.9 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H - MEDIUM 4.9 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H