DEBIAN-CVE-2026-18103
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.
DEBIAN-CVE-2026-18103
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:DEBIAN-CVE-2026-18103
isc-dhcp
Source reference: /affected/0/package/name
- Affected versions
- 4.4.3-P1-2
Source reference:
/affected/0/versions4.4.3-P1-3Source reference:
/affected/0/versions4.4.3-P1-4Source reference:
/affected/0/versions4.4.3-P1-5Source reference:
/affected/0/versions4.4.3-P1-5~exp1Source reference:
/affected/0/versions4.4.3-P1-5~exp2Source reference:
/affected/0/versions4.4.3-P1-6Source reference:
/affected/0/versions4.4.3-P1-7Source reference:
/affected/0/versions4.4.3-P1-8Source reference:
/affected/0/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
isc-dhcp
Source reference: /affected/1/package/name
- Affected versions
- 4.4.3-P1-8
Source reference:
/affected/1/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "isc-dhcp",
"purl": "pkg:deb/debian/isc-dhcp?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"4.4.3-P1-2",
"4.4.3-P1-3",
"4.4.3-P1-4",
"4.4.3-P1-5",
"4.4.3-P1-5~exp1",
"4.4.3-P1-5~exp2",
"4.4.3-P1-6",
"4.4.3-P1-7",
"4.4.3-P1-8"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-18103.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "isc-dhcp",
"purl": "pkg:deb/debian/isc-dhcp?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"4.4.3-P1-8"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-18103.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #56143 · Revision 1
- Added to Heist Feed
- Publisher date