Package Instance

MikroORM has Prototype Pollution in Utils.merge
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.

Exploitation requires application code to pass untrusted user input into ORM operations that merge object structures, such as entity property assignment or query condition construction.

Prototype pollution may lead to denial of service or unexpected application behavior. In certain scenarios, polluted properties may influence query construction and potentially result in SQL injection depending on application code.

MikroORM is vulnerable to SQL Injection via specially crafted object
## Summary

MikroORM versions <= 6.6.9 and <= 7.0.5 are vulnerable to SQL injection when specially crafted objects are interpreted as raw SQL query fragments.

## Impact

If user-controlled input is passed directly to MikroORM query construction APIs, an attacker may inject raw SQL fragments. This can lead to SQL injection depending on the database and query being executed.

## Affected usage

The issue occurs when untrusted objects are passed to ORM write APIs such as:

- `wrap(entity).assign(userInput)` followed by `em.flush()`
- `em.nativeUpdate()`
- `em.nativeInsert()`
- `em.create()` followed by `em.flush()`

Applications that validate input types or enforce strict schema validation before passing data to MikroORM are not affected.

## Fix

The vulnerability was caused by duck-typed detection of internal ORM marker properties.

The fix replaces these checks with symbol-based markers that cannot be reproduced by user input.