Submitted by bin2chen, also found by oakcobalt
In YieldEthStakingLido, the main processes are as follows:
The issue is the second step, unstETH is with a maximum withdrawal limit: MAX_STETH_WITHDRAWAL_AMOUNT
https://docs.lido.fi/contracts/withdrawal-queue-erc721/#requestwithdrawals
Current configuration here.
lido suggests that if it exceeds this value, it needs to be taken in batches, but YieldEthStakingLido.sol can only be taken at once. If the stake amount exceeds this value, it will not be possible to unstake() and the token will be locked in the contract.
Assumption: leverageFactor = 50000 , eth price = $2500
As long as the value of the nft is greater than 1000 * $2500 / 5 = $500,000 it will be possible to stake() more than MAX_STETH_WITHDRAWAL_AMOUNT.
After that, when the user performs an unstake() it will fail, causing the token to be locked.
Excessive amount of stake will result in failure to unstake().
YieldStakingBase add  method checkStakeAmount. Each sub contract override implements its own maximum amount limit, YieldEthStakingLido suggests a maximum of MAX_STETH_WITHDRAWAL_AMOUNT/2.
Context
0xTheC0der (judge) decreased severity to Medium and commented:
thorseldon (BendDAO) confirmed and commented:
