BNB Chain Got a Major Security And Throughput Upgrade

BNB Chain has activated the Pasteur hardfork on BSC Mainnet, delivering a package of upgrades targeting bridge security, validator governance, and block capacity. The release bundles three BNB Evolution Proposals, each addressing a distinct weakness in the network's existing architecture.

Closing Security Gaps in Bridges and Validator Keys

BEP-682 addresses a vulnerability in the cross-chain bridge verification process. Before the upgrade, the system did not prevent the same validator from appearing multiple times in an approval list, meaning a carefully constructed request could count one validator's voting weight more than once and allow a transfer to pass with fewer genuine approvals than the rules required. BEP-682 closes that gap by explicitly rejecting duplicate validator entries, ensuring bridge approvals reflect a true supermajority.

BEP-695 tackles a separate governance risk. When validators rotate their consensus keys, old keys could continue to hold management rights after replacement. The upgrade removes those privileges once a new key is in use, and also ensures blacklisted addresses can no longer participate in governance voting.

More Capacity Without Changing Block Times

The performance side of the fork centres on BEP-675. Currently, validators execute transactions a second time before signing, even though builders already executed them before submitting the block. Within BSC's 450-millisecond block interval, that duplication consumes valuable time. BEP-675 allows builders to submit blocks that have already been executed, so validators can check, sign, and broadcast without repeating the full execution step inside the critical production window.

Internal testing showed meaningful gains from this change. Throughput climbed by roughly 88% under a controlled workload, with transactions per second rising from around 1,237 to 2,324, and average block gas usage increasing from approximately 46 million to 84 million against a 100 million limit. BNB Chain was clear that these figures reflect testnet conditions and not live mainnet performance.

BNB Chain has stated a goal of doubling mainnet throughput during the second half of 2026, and the Pasteur fork represents a direct step toward that target. Earlier 2026 releases, including the Fermi fork in January, focused primarily on cutting block times. Pasteur takes a different approach, using the existing block cadence more productively while tightening security controls around bridge verification and validator authority.

Sources:
CoinTelegraph: BNB Chain Activates Pasteur Hard Fork on BSC
CryptoNews: BNB Chain Schedules Security-Focused Pasteur Hard Fork
Crypto Briefing: Pasteur Hardfork Scheduled for BSC Mainnet