Canceled NFT Listing Sold for $14.8K in OpenSea’s Latest Blunder

The newest development in the OpenSea NFT debacle shows us that the NFT marketplace’s mistakes continue to cost its users more and more every day. The victim of this oversight lost their NFT due to advice by OpenSea themselves.

OpenSea Openly Screws Up

NFT trader and artist swolfchan.eth mentioned in a tweet that the most recent community update from Opensea asked its users to cancel all listings of their NFTs. They mentioned that their NFTs could be sold if their older listing was still active.

So i got two emails today from @opensea about listings, and lost 15 ETH+ from exactly what their trying to prevent…

I was told to please act urgently to cancel any inactive listings… cancelled a 15 ETH MAYC @BoredApeYC and it triggered a 6 ETH listing… and sold?? pic.twitter.com/1wt21mt9mz

— swolfchan.eth (@swolfchan) January 27, 2022

Thus following the instructions, the user went ahead and canceled the listing and soon after discovered that their 15 ETH ($36.7k) worth of MAYC Bored Ape NFT was sold for just 6 ETH which is a little under $15k.

The incident took place when the cancellation of an older listing of the same NFT for 6 ETH was found by an exploiter who managed to execute the sale before the cancellation transaction could be completed. 

As explained by another NFT collector, dingaling on Twitter:

“Well, checking the mempool is much easier than scraping all the Opensea APIs to find old orders, since the cancellation tx submitted has all the order details in the tx input data. You are basically handing out your NFT listing details on a silver platter to be frontrun”

When a pending transaction is in the mempool, exploiters can easily access that info and if they act quickly, they can purchase the NFT off of the market even before the listing is canceled.

He went on to say that OpenSea’s incompetence enabled these exploiters to receive the exact information needed to make the purchase at an older lower price when they asked their users to cancel the listings.

What NOT To Do

Twitter user dingaling further explained that users can prevent a similar situation by canceling their listings the right way.

“Make sure you transfer all the NFTs with “inactive Opensea listings” OUT of your address first before cancelling the live listings in your original address. Only after all the listings are cancelled are you safe to transfer it back.”

The whole situation is a continuation of the OpenSea disaster from 3 days ago when an “Opportunistic Buyer” managed to steal more than $751k worth of NFTs by exploiting older listings of certain NFTs.

Although OpenSea has since reimbursed the losses, another fault on their end has once again left its users outraged.