CVE-2018-17228: nmap4j 1.1.0 allows attackers to execute arbitrary commands via shell metacharacters in an includeHosts call.

This week

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2018-17228 is a critical-severity flaw (CVSS 9.8) affecting nmap4j. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

nmap4j 1.1.0 allows attackers to execute arbitrary commands via shell metacharacters in an includeHosts call.

Why this priority

Critical severity
Public exploit reference
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.6% (top 24%)
CISA exploited list	No
Weakness	CWE-78
Published	2018-09-19
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: nmap4j project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2018-09-19 21:29 UTCPublished CVE record published
2026-06-17 01:45 UTCUpdated Record last modified

nmap4j project nmap4j DOWNGRADE

Affected: 1.1.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.1.0

1. Check installed version

apt-cache policy nmap4j || rpm -q nmap4j || nmap4j --version

2. No fixed release: DOWNGRADE to a release before 1.1.0 (Debian / Ubuntu)

apt-cache madison nmap4j sudo apt install nmap4j=<VERSION_BEFORE_1.1.0> sudo apt-mark hold nmap4j

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list nmap4j sudo dnf downgrade nmap4j-<VERSION_BEFORE_1.1.0> sudo dnf versionlock add nmap4j

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2018-17228?

nmap4j: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2018-17228 being exploited?

CVE-2018-17228 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2018-17228 affect?

CVE-2018-17228 affects nmap4j. Severity is critical (CVSS 9.8). nmap4j 1.1.0 allows attackers to execute arbitrary commands via shell metacharacters in an includeHosts call.

How urgent is CVE-2018-17228?

Priority 63/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

References

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