BNB Chain, Base and Mantle Network moved quickly this week to contain a state-root calculation bug in the Reth Ethereum execution client, a flaw that could have caused affected nodes to compute incorrect blockchain states across several EVM-compatible networks.
BNB Chain said on November 6 that it was aware of the security risk affecting Reth. The team clarified that opBNB does not use op-reth, and the impact on BSC-Reth remains limited. Developers were preparing a hotfix and monitoring the situation, with no user action required at the time.
Base reported that it identified the vulnerability on November 4 and patched all block-building nodes the same day. The Coinbase-backed layer 2 network recalculated its state root and confirmed it matched the correct value. Base released version 1.5.3 on November 5 at 17:52 UTC and advised node operators to upgrade; the maintenance window runs until November 7 at 16:19 UTC. Base said user funds were unaffected and no node resynchronization was required.
The underlying issue was fixed in Reth version 2.10.0 and related software, including op-reth 2.8.1. Blockchain security firm Blockaid said unpatched clients could suffer synchronization problems or return incorrect proofs through the eth_getProof interface, but described the problem as a correctness bug rather than an exploit, with no known financial losses.
Mantle Network also announced its own mitigation, shipping op-reth version 1.6.3 to address the state-root bug. The team confirmed user assets were safe, no database migration was necessary, and node operators were encouraged to update. LayerZero temporarily suspended some off-chain infrastructure connected to affected networks as a precaution, delaying certain cross-chain messages but not causing message loss.
