> For the complete documentation index, see [llms.txt](https://reports.immunefi.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://reports.immunefi.com/alchemix-v3/57448-sc-insight-unnecessary-computation-of-lockedcollateral-in-adddebt-and-subdebt.md).

# 57448 sc insight unnecessary computation of lockedcollateral in adddebt and subdebt 

**Submitted on Oct 26th 2025 at 10:01:53 UTC by @algiz for** [**Audit Comp | Alchemix V3**](https://immunefi.com/audit-competition/alchemix-v3-audit-competition)

* **Report ID:** #57448
* **Report Type:** Smart Contract
* **Report severity:** Insight
* **Target:** <https://github.com/alchemix-finance/v3-poc/blob/immunefi\\_audit/src/AlchemistV3.sol>
* **Impacts:**

## Description

## Brief/Intro

Locked collateral is computed in both `_addDebt()` and `_subDebt()`, although it has already been updated by the `_sync()`

## Vulnerability Details

Both `_addDebt()` and `_subDebt()` calculate the locked collateral:

```solidity
uint256 lockedCollateral = convertDebtTokensToYield(account.debt) * minimumCollateralization / FIXED_POINT_SCALAR;
```

which makes an external call to the Morpho vault.

* `_addDebt()` is called from `_mint()`, which is called in `_mint()` and `_mintFrom()`
* `_subDebt()` is called from `burn()`, `repay()`, `_forceRepay()` and `_doLiquidation()` (which is called from `_liquidate()`)

In any of those cases the `_sync()` function has been called prior, hence the locked collateral has been already calculated and up to date in `rawLocked`:

```solidity
// Update locked collateral
        account.rawLocked = convertDebtTokensToYield(account.debt) * minimumCollateralization / FIXED_POINT_SCALAR;
```

## Impact Details

Unnecessary calculation with external call that costs additional gas.

## References

n/a

## Proof of Concept

## Proof of Concept

provided in the Impact details section


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.

Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:

```
GET https://reports.immunefi.com/alchemix-v3/57448-sc-insight-unnecessary-computation-of-lockedcollateral-in-adddebt-and-subdebt.md?ask=<question>&goal=<user_goal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.