Submitted by Jujic, also found by gzeon
There is no upper limit on poolColl.tokens[], it increments each time  when a new collateral is added. Eventually, as the count of collateral increases, gas cost of smart contract calls will raise  and that there is no implemented function to reduce the array size.
For every call  getVC() function which computed  contain the VC value of a given collateralAddress is listed in poolColl.tokens[] array, the gas consumption can be more expensive each time that a new collateral address is appended to the  array, until reaching an Out of Gas error or a Block Gas Limit in the worst scenario.
https://github.com/code-423n4/2021-12-yetifinance/blob/5f5bf61209b722ba568623d8446111b1ea5cb61c/packages/contracts/contracts/ActivePool.sol#L268
https://github.com/code-423n4/2021-12-yetifinance/blob/5f5bf61209b722ba568623d8446111b1ea5cb61c/packages/contracts/contracts/DefaultPool.sol#L184
Remix
Arrays length should be checked.
kingyetifinance (Yeti finance) confirmed and disagreed with severity:
