CVE-2018-16489: Just-Extend Project Just-Extend

Critical severity, CVSS 9.8. EPSS: 1.8% chance of exploitation in the next 30 days.

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

Affected products

• Just-Extend Project Just-Extend: before 4.0.0 (fixed in 4.0.0)

Published 2019-02-01. Last modified 2026-06-17.