Blockaid warned on Nov. 5 that a bug in the reth execution client and software built on it, including op-reth, can make nodes compute incorrect state roots. Unpatched nodes may stall or return incorrect state proofs, the firm said.
“It's a correctness bug, not an exploit,” Blockaid said, reporting no known loss of funds. Its alert covers reth-based clients on several Ethereum-compatible networks, including many OP Stack chains.
https://x.com/i/status/2118405438291198020
The risk concerns the software that executes transactions and maintains a node's view of the blockchain. Optimism's op-reth documentation says the client executes Layer 2 blocks, maintains chain state and answers requests from applications. Incorrect proofs can undermine the verification those applications depend on.
Patched Builds Are Available
Blockaid identified three patched releases:
The upstream reth fix was merged Nov. 3. Base's release notes explicitly say its update prevents a state-root mismatch and recommend that Base Mainnet and Sepolia operators upgrade at their earliest convenience.
Celo and Mantle developers also merged backports, applying the correction to older software lines. Mantle's patch targets its v1.6.2 production line. Blockaid's alert did not specify the full range of vulnerable versions.
Blockaid urged node operators and RPC providers to upgrade, and protocols and bridges to confirm that their providers are patched.
Why Incorrect Proofs Matter
Celo's patch explanation describes how the bug can skip a newly inserted entry when updating the data structure used to calculate a state root—the cryptographic summary against which account and contract-storage data can be checked.
The eth_getProof specification describes proofs that let applications verify account and storage values against a block's state root. That makes the distinction between a node's response and a trusted root crucial for bridges, light clients and contracts relying on such proofs: an incorrect response is not automatically a valid authorization to move funds.
For example, Optimism's withdrawal specification requires an inclusion proof for a withdrawal message and says the transaction reverts if proof verification fails. Bad proof data can therefore prevent verification rather than establish a successful theft.
The precautions have already reached DeFi users. Gauntlet said it was closing V1 vault supply queues, pausing allocations and reducing exposure to LayerZero-bridged assets, as The Defiant previously reported. Frax said its assets and contracts were unaffected and operating normally, while certain LayerZero routes were temporarily paused.
Blockaid said LayerZero had paused offchain infrastructure on some affected chains until each confirms it is patched, describing messages as “delayed, not lost.”