CVE-2018-16491: A prototype pollution vulnerability was found in node.extend <1.1.7, ~<2.0.1 that allows an attacker to inject

Q: How do I fix CVE-2018-16491?

node.extend: upgrade to 1.1.7, 2.0.1. Exact commands for each OS are on this page.

Q: Is CVE-2018-16491 being exploited?

CVE-2018-16491 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2018-16491 affect?

CVE-2018-16491 affects node.extend. Severity is critical (CVSS 9.8). A prototype pollution vulnerability was found in node.extend <1.1.7, ~<2.0.1 that allows an attacker to inject arbitrary properties onto Object.prototype.

Q: How urgent is CVE-2018-16491?

Priority 64/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

CRITICAL 9.8REMOTEUPGRADE

CVE-2018-16491 is a critical-severity flaw (CVSS 9.8) affecting node.extend. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A prototype pollution vulnerability was found in node.extend <1.1.7, ~<2.0.1 that allows an attacker to inject arbitrary properties onto Object.prototype.

Why this priority

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

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.7% (top 23%)
CISA exploited list	No
Weakness	CWE-400, CWE-74
Published	2019-02-01
Last modified	2026-06-17

Publisher (CNA): HackerOne · Vendor: dreamerslab

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

Am I affected?

Timeline

2019-02-01 18:29 UTCPublished CVE record published
2026-06-17 01:44 UTCUpdated Record last modified

dreamerslab node.extend UPGRADE

Affected: < 1.1.7 · >= 2.0.0 and < 2.0.1

Fixed in: 1.1.7, 2.0.1

Safe to downgrade to: a release before 2.0.0

1. Check installed version

npm ls node.extend

2. UPGRADE to 1.1.7

npm install node.extend@">=1.1.7"

3. If no update is available yet, DOWNGRADE to a release before 2.0.0

npm view node.extend versions npm install node.extend@"<2.0.0"

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-2018-16491?

node.extend: upgrade to 1.1.7, 2.0.1. Exact commands for each OS are on this page.

Is CVE-2018-16491 being exploited?

CVE-2018-16491 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-2018-16491 affect?

CVE-2018-16491 affects node.extend. Severity is critical (CVSS 9.8). A prototype pollution vulnerability was found in node.extend <1.1.7, ~<2.0.1 that allows an attacker to inject arbitrary properties onto Object.prototype.

How urgent is CVE-2018-16491?

Priority 64/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

References

← Back to latest CVEs