How severe is CVE-2018-16489?

CVE-2018-16489 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2018-16489 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-16489?

CVE-2018-16489 affects Just-extend Project Just-extend. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-16489?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2018-16489 published?

CVE-2018-16489 was published on 2019-02-01 and last updated on 2026-06-17.

CVE-2018-16489

CVE-2018-16489 is a critical-severity vulnerability in Just-extend Project Just-extend with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-74.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (76th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-74
Affected product: Just-extend Project Just-extend
Published: 2019-02-01
Last modified: 2026-06-17

Description

A prototype pollution vulnerability was found in just-extend <4.0.0 that allows attack to inject properties onto Object.prototype through its functions.

Frequently asked questions

What is CVE-2018-16489?: A prototype pollution vulnerability was found in just-extend <4.0.0 that allows attack to inject properties onto Object.prototype through its functions.
How severe is CVE-2018-16489?: CVE-2018-16489 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-16489 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-16489?: CVE-2018-16489 affects Just-extend Project Just-extend. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-16489?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2018-16489 published?: CVE-2018-16489 was published on 2019-02-01 and last updated on 2026-06-17.

References

https://hackerone.com/reports/430291

Affected products (1)

cpe:2.3:a:just-extend_project:just-extend:*:*:*:*:*:node.js:*:*

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