EVM / Solidity Error 0x4e487b71: Panic(0x11): arithmetic overflow/underflow

Identify: does your log match?

ContractFunctionExecutionError: The contract function "claim" reverted with the following reason:
Arithmetic operation resulted in underflow or overflow.

Contract Call:
  address:   0xe7f1725E7734CE288F8367e1Bb143E90bb3F0512
  function:  claim(uint256 amount)
  args:           (5000000000000000000)

Raw revert data:
0x4e487b710000000000000000000000000000000000000000000000000000000000000011

Version: viem@2.21.37

1. High

   Subtracting a larger value

   balance - amount or end - start where the right side is bigger. 0.8.x checked math reverts with Panic(0x11) instead of wrapping.

2. Medium

   Overflow in multiplication

   amount * price * 1e18 exceeds 2^256-1 for large inputs, or a downcast like uint128(x) overflows via explicit math.

3. Medium

   Decrementing a zero counter

   totalStaked-- or count -= 1 after state was already cleared by another path.

Fix

function claim(uint256 amount) external {
    rewards[msg.sender] -= amount; // Panic(0x11) if amount > rewards
    token.transfer(msg.sender, amount);
}

error ClaimExceedsRewards(uint256 available, uint256 requested);

function claim(uint256 amount) external {
    uint256 available = rewards[msg.sender];
    if (amount > available) revert ClaimExceedsRewards(available, amount);
    unchecked { rewards[msg.sender] = available - amount; }
    token.safeTransfer(msg.sender, amount);
}

Verify: reproduce it on purpose

$ cast decode-error 0x4e487b710000000000000000000000000000000000000000000000000000000000000011 --sig "Panic(uint256)"

Prevent

• Fuzz arithmetic with forge test --fuzz-runs 10000.
• Use SafeCast for downcasts.
• Treat any Panic in production as a bug, not a user error.