A user with access to the DB could craft a database entry that would result in executing code on Triggerer - which gives anyone who have access to DB the same permissions as Dag Author. Since direct DB access is not usual and recommended for Airflow, the likelihood of it making any damage is low.
You should upgrade to version 6.0.0 of the provider to avoid even that risk.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v3.1