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.
History

Tue, 31 Mar 2026 16:00:00 +0000

Type Values Removed Values Added
Description 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.
Title MikroORM has Prototype Pollution in Utils.merge
Weaknesses CWE-1321
References
Metrics cvssV4_0

{'score': 8.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:L/SA:L'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-03-31T18:52:43.939Z

Reserved: 2026-03-26T15:57:52.324Z

Link: CVE-2026-34221

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-03-31T16:16:32.293

Modified: 2026-03-31T16:16:32.293

Link: CVE-2026-34221

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.