No exploitation reported

CVE-2018-5733

No exploitation reported by the sources we read.

Published2019-01-16
WeaknessCWE-190

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A malicious client which is allowed to send very large amounts of traffic (billions of packets) to a DHCP server can eventually overflow a 32-bit reference counter, potentially causing dhcpd to crash. Affects ISC DHCP 4.1.0 -> 4.1-ESV-R15, 4.2.0 -> 4.2.8, 4.3.0 -> 4.3.6, 4.4.0.

Timeline

dates in UTC

2019-01-1620:29CVE publishedNVD
2026-10-2319:23EPSS crossed 10 %FIRST EPSS

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2018-5733?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2018-5733?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Isc dhcp

Branch	Affected	Fixed in	Source
4.2	≥ 4.2.0, ≤ 4.2.8	no fix published	NVD
4.3	≥ 4.3.0, ≤ 4.3.6	no fix published	NVD
4.1	= 4.1-esv	no fix published	NVD
4.1	= 4.1.0	no fix published	NVD
4.4	= 4.4.0	no fix published	NVD

Canonical ubuntu linux

Branch	Affected	Fixed in	Source
14.4	= 14.04	no fix published	NVD
16.4	= 16.04	no fix published	NVD
17.10	= 17.10	no fix published	NVD

Debian debian linux

Branch	Affected	Fixed in	Source
7.0	= 7.0	no fix published	NVD
8.0	= 8.0	no fix published	NVD
9.0	= 9.0	no fix published	NVD

5 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

kb.isc.orgVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.17.5read 2026-10-23
CNACVSS 3.05.9read 2026-10-23
NVDCVSS 2.05read 2026-10-23
NVDweakness (CWE)CWE-190read 2026-10-23
FIRST EPSSEPSS score20.2 %read 2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: 2019-01-16
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2018-5733?

Is CVE-2018-5733 actively exploited?

Active exploitation of CVE-2018-5733 has not been confirmed. Its EPSS score was 20.2% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2018-5733?

CVE-2018-5733 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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