A prototype pollution vulnerability exists in Rocket.Chat server <5.2.0 that could allow an attacker to a RCE under the admin account. Any user can create their own server in your cloud and become an admin so this vulnerability could affect the cloud infrastructure. This attack vector also may increase the impact of XSS to RCE which is dangerous for self-hosted users as well.
CWE-77, CWE-1321, CWE-1321