The Solana Foundation has permanently removed 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 the expulsions, stating that the foundation identified operators involved in mempool activities facilitating sandwich attacks. He said:

“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. This tactic violates the Solana Foundation’s rules, according to Garcia.

**Protecting Retail Users**

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

“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.”

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

In May, Solana validators' earnings from MEV surpassed those of the Ethereum blockchain. MEV revenue has been growing rapidly since mid-March, recently accelerating to record highs. One Solana-based protocol, Jito, is projected to generate approximately $25 million in revenue over the next 12 months by 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 stop delegating to those exploiting retail users through sandwich attacks. Although 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.”

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