Mutuum Contracts - Mutuum Finance

1. Introduction

Mutuum Finance engaged Halborn to perform a security assessment of their EVM smart contracts from November 18th, 2025, to November 26th, 2025. The assessment scope was limited to the smart contracts provided to Halborn. Commit hashes and additional details are available in the Scope section of this report.

The Mutuum Finance codebase in scope consists of solidity smart contracts that implement an aave inspired staking mechanism with additional features like dynamic exchange rate, and revised slashing mechanism.

2. Assessment Summary

Halborn was allocated 7 days for this engagement and assigned 1 full-time security engineer to conduct a comprehensive review of the smart contracts within scope. The engineer is an expert in blockchain and smart contract security, with advanced skills in penetration testing and smart contract exploitation, as well as extensive knowledge of multiple blockchain protocols.

The objectives of this assessment were to:

• Identify potential security vulnerabilities within the smart contracts.

• Verify that the smart contract functionality operates as intended.

In summary, Halborn identified some areas for improvement to reduce the likelihood and impact of potential risks, which were mostly addressed by the Mutuum Finance team. The primary recommendations were as follows:

• Consider modifying the stake function to make sure that zero shares should not be minted

• Consider deriving totalStaked on-chain directly from the referenced staking token’s totalSupply wherever it is feasible.

• Consider validating cooldownSeconds and unstakeWindow at pool creation time to ensure their sum stays within a safe bound.

• Consider introducing bounds checks on the allowable range of expo + targetDecimals before computing the power of ten, reverting with a clear error if the combination would exceed a predefined maximum.