Block stuffing is a form of denial-of-service attack where malicious actors flood blockchains with low-value transactions to consume blockspace. This causes delays, raises fees, and can disrupt user activity, MEV strategies, or on-chain governance. Common on Ethereum, Cosmos, and Solana, it exploits the economic limits of block capacity. While defenses exist—like EIP-1559, spam filtering, and rate limits—block stuffing remains a persistent challenge. Understanding its mechanics helps developers, validators, and users build and support more resilient blockchain ecosystems.
Q1: What is the primary goal of a block stuffing attack?
A1: Fill blockspace to deny access to others
Q2: Which of the following is a possible motive for block stuffing?
A2: Delay rival bots or protocols
Q3: What type of transactions are typically used in block stuffing attacks?
A3: Revertable or spammy low-cost transactions
Q4: What is a major risk of ongoing block stuffing on a blockchain network?
A4: Users face high fees and slow confirmations
