CVE-2018-12123: Node.js: All versions prior to Node.js 6.15.0, 8.14.0, 10.14.0 and 11.3.0: Hostname spoofing in URL parser for

Routine

MEDIUM 4.3UPGRADE

CVE-2018-12123 is a medium-severity flaw (CVSS 4.3) affecting node.js. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Node.js: All versions prior to Node.js 6.15.0, 8.14.0, 10.14.0 and 11.3.0: Hostname spoofing in URL parser for javascript protocol: If a Node.js application is using url.parse() to determine the URL hostname, that hostname can be spoofed by using a mixed case "javascript:" (e.g. "javAscript:") protocol (other protocols are not affected). If security decisions are made about the URL based on the hostname, they may be incorrect.

Why this priority

EPSS top 9%: very likely to be exploited

A fixed release or distro patch exists.

Risk facts

CVSS score	4.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	4.0% (top 9%)
CISA exploited list	No
Weakness	CWE-115, CWE-20
Published	2018-11-28
Last modified	2026-10-08

Publisher (CNA): Node.js · Vendor: nodejs

Last updated 2026-10-08 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2018-11-28 17:29 UTCPublished CVE record published
2026-10-08 22:16 UTCUpdated Record last modified

nodejs node.js UPGRADE

Affected: >= 6.0.0 and < 6.15.0 · >= 8.0.0 and < 8.14.0 · >= 10.0.0 and < 10.14.0 · >= 11.0.0 and < 11.3.0

Fixed in: 6.15.0, 8.14.0, 10.14.0, 11.3.0

Safe to downgrade to: a release before 6.0.0

1. Check installed version

apt-cache policy node.js || rpm -q node.js || node.js --version

2. UPGRADE to 6.15.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade node.js

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade node.js

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 6.0.0 (Debian / Ubuntu)

apt-cache madison node.js sudo apt install node.js=<VERSION_BEFORE_6.0.0> sudo apt-mark hold node.js

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list node.js sudo dnf downgrade node.js-<VERSION_BEFORE_6.0.0> sudo dnf versionlock add node.js

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-2018-12123?

node.js: upgrade to 6.15.0, 8.14.0, 10.14.0, 11.3.0. Exact commands for each OS are on this page.

Is CVE-2018-12123 being exploited?

CVE-2018-12123 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-2018-12123 affect?

CVE-2018-12123 affects node.js. Severity is medium (CVSS 4.3). Node.js: All versions prior to Node.js 6.15.0, 8.14.0, 10.14.0 and 11.3.0: Hostname spoofing in URL parser for javascript protocol: If a Node.js application is using url.parse() to determine the URL hostname, that hostname can be spoofed by

How urgent is CVE-2018-12123?

Priority 38/100. EPSS top 9%: very likely to be exploited

Software pages

Node.js vulnerabilities

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References

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