CVE-2026-34221
Published:March 31, 2026
Updated:April 23, 2026
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.
Affected Packages
@mikro-orm/core (NPM):
Affected version(s) >=7.0.0-dev.0 <7.0.6Fix Suggestion:
Update to version 7.0.6@mikro-orm/core (NPM):
Affected version(s) >=4.0.0-alpha.0 <6.6.10Fix Suggestion:
Update to version 6.6.10Additional Notes
The description of this vulnerability differs from MITRE.
Related Resources (3)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
PRESENT
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
LOW
Subsequent System Availability
LOW
CVSS v3
Base Score:
10
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
EPSS
Base Score:
0.10
