CVE-2026-34221

CRITICAL

MikroORM has Prototype Pollution in Utils.merge

Title source: cna
STIX 2.1

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.

Scores

CVSS v3 9.1
EPSS 0.0013
EPSS Percentile 32.6%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-1321
Status published
Products (4)
mikro-orm/core 0 - 6.6.10npm
mikro-orm/mikro-orm < 6.6.10
mikro-orm/mikro-orm >= 7.0.0-rc.0, < 7.0.6
mikro-orm/mikroorm < 6.6.10
Published Mar 31, 2026
Tracked Since Mar 31, 2026