Hawk High

Summary graduateAndUpgrade may revert if any teacher's address cannot receive USDC tokens.

Vulnerability Details A single failed transfer could block the entire upgrade process. with the teacher list scaling up, the likihood increased to the point that this function is almost not useable .

Impact entire graduateAndUpgrade process will fail if even one transfer fails. This not only prevents the upgrade but also halts the distribution of funds to all teachers and the principal. It effectively renders the function unusable in a real-world scenario with a large teacher list, undermining the contract's core functionality.

Tools Used manual review

Recommendations

1. Implement batch payment logic with error handling to skip failed transfers and continue processing the rest.

2.Validate teacher addresses before adding them to listOfTeachers to ensure they can receive USDC

tokens.