CVE-2026-16266

Medium severity, CVSS 4.0. EPSS: 0.4% chance of exploitation in the next 30 days.

Versions of the package mongo-object before 3.0.3 are vulnerable to Prototype Pollution via the expandKey() function in util.js. An attacker can modify the JavaScript prototype chain by supplying a crafted property path containing special keys such as __proto__.

Published 2026-07-21. Last modified 2026-07-23.