MetaMask has launched a new security feature that helps block so-called "red pill" attacks when interacting with Ethereum and other EVM-based apps. The tool compares the transaction preview with the actual outcome after execution, and if there's a mismatch, MetaMask automatically cancels the transaction.

How the Protection Works

Before you hit send, MetaMask shows a preview of what the transaction should do. After the transaction runs, MetaMask checks if the real result matches the preview. If there's any difference, the transaction doesn't go through and your funds stay safe. This tackles the risk of last-minute transaction outcome swaps—what's known as a red pill attack—right at the execution stage.

Where You Can Use It

This protection is live in MetaMask extension v13.45 and works across 13 EVM networks that support smart accounts (EIP-7702).

What This Means for Users

This new check makes your transactions more predictable: what you see before confirming is exactly what happens on-chain. If not, MetaMask cancels the transaction automatically. It adds an extra layer of security without changing how you use dApps, and helps cut down on the risk of nasty surprises when you send a transaction.