Solana Foundation expels validators for sandwich attacks on retail users

The Solana Foundation has expelled several validators from its delegation program for conducting sandwich attacks on retail users.

In a recent Discord announcement, Tim Garcia, the Team Lead of Solana Validator Relations, confirmed that the removals were permanent, stating that the foundation identified operators involved in mempool activities supporting sandwich attacks.

He stated:

“Enforcement actions are ongoing as we detect operators participating in mempools which allow sandwich attacks.”

A sandwich attack involves placing two transactions around a target transaction to manipulate the price and profit from the difference. According to Garcia, this tactic violates the Solana Foundation’s rules.

Protecting retail users

Mert Mumtaz, co-founder of Helius, explained that some validators were using these attacks to secure better prices for themselves at the expense of retail traders.

“A sandwich attack is a malicious form of MEV attack that ensures retail always gets the worst possible price while extracting all the profit for themselves,” Mumtaz said.

Maximal Extractable Value (MEV) allows validators to manipulate user transactions to boost profits. This manipulation can occur through front-running and sandwich attacks, influencing transaction prices and profiting from the resulting changes.

In May, Solana validators’ earnings from MEV flipped that of the Ethereum blockchain. The MEV revenue has been growing rapidly since mid-March but has recently accelerated to record highs. Interestingly, one Solana-based protocol, Jito, is set to generate approximately $25 million in revenue over the next 12 months, according to Token Terminal. Its business model involves taking a 5% cut of the MEV tips paid to Solana validators.

In response to the validators’ removal, Mumtaz stated that the Solana Foundation would cease delegating to those exploiting retail users through sandwich attacks. Though these operators can continue their activities on the network, they will no longer receive support or delegation from the foundation. He added:

“Most importantly, these operators can still do whatever they want; it’s a permissionless network—it just won’t be Foundation subsidized.”

Members of the crypto community have criticized the move, suggesting it further highlights Solana’s centralization compared to other chains. Solana has previously been criticized for centralization when it has shut down the network for prolonged periods. Members of the Solana Foundation have attempted to debunk such theories, including in an interview with CryptoSlate on the SlateCast.