Vulnerability Details CVE-2026-34221
MikroORM is a TypeScript ORM for Node.js based on Data Mapper, Unit of Work and Identity Map patterns. Prior to versions 6.6.10 and 7.0.6, a prototype pollution vulnerability exists in the Utils.merge helper used internally by MikroORM when merging object structures. The function did not prevent special keys such as __proto__, constructor, or prototype, allowing attacker-controlled input to modify the JavaScript object prototype when merged. This issue has been patched in versions 6.6.10 and 7.0.6.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.0
EPSS Ranking 14.0%
CVSS Severity
CVSS v3 Score 9.1