Vulnerability · Published Mar 31, 2026 · Assigned by GitHub_M
CVE-2026-34221MikroORM has Prototype Pollution in Utils.merge
High 8.3
In plain English
A high-severity prototype pollution in mikro-orm from mikro-orm. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | @mikro-orm/core | 6.6.10 | GHSA-qpfv-44f3-qqx6 |
| npm | @mikro-orm/core | 7.0.6 | GHSA-qpfv-44f3-qqx6 |
Affected products (as reported)
Weakness: CWE-1321 · 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
References
- https://github.com/mikro-orm/mikro-orm/security/advisories/GHSA-qpfv-44f3-qqx6 x_refsource_CONFIRM