### Impact
An authenticated attacker can instantiate any class in the PHP application by using the `embed_key` parameter across multiple API endpoints. The instantiation is performed by the Laravel container. As a result, the `__construct()` method of the class is called and all constructor dependencies are resolved. The attacker cannot specify parameter values and cannot call any arbitrary method.
### Patches
The problem has been patched in 9.23.0 and pre-release version 10.0.0-beta.4. An additional check was added to verify that `embed_key` is a class extending `SharpFormEditorEmbed` before any instantiation.
### Workarounds
No known workarounds.