BNB Chain activated the Pasteur hard fork on BNB Smart Chain mainnet at 02:30 UTC on Aug. 25, introducing three changes focused on bridge security, validator authorization and block capacity, crypto.news reported .
The fork proceeded without major disruption, with BSC continuing to produce blocks at its existing 450-millisecond interval.
What Pasteur changes
Pasteur combines BEP-682, BEP-695 and BEP-675 under the broader BEP-673 upgrade plan, and the changes had run on BSC’s Chapel testnet since July 21 before reaching mainnet. BEP-682 changes how the network verifies light blocks submitted through cross-chain infrastructure: it now rejects duplicate validator entries before calculating whether a voting threshold has been reached, closing a gap that could have made a bridge approval appear to carry more independent support than it actually did.
Validator and governance fixes
BEP-695 closes gaps around validator key rotation, penalties and governance. When a validator replaces its operator key, the previous key now loses its management rights, and validators cannot escape pending penalties by rotating keys. The updated contracts also check the original signer before counting a delegated vote, blocking restricted addresses from using offchain signatures to participate in governance. Node operators were required to run client v1.7.7 for the upgrade.
More room for transactions
BEP-675 introduces an optional route for specialist builders to submit blocks they have already executed, letting validators sign without re-running full execution. Builders can keep using the previous process, and the new route must be enabled through the network’s remote procedure call interface. In controlled QANet testing, throughput rose from 1,237 to 2,324 transactions per second while average gas consumption per block rose from 46.35 million to 84.15 million and the 450-millisecond block time and 100-million gas limit stayed unchanged. BNB Chain noted the performance figures came from controlled testing rather than mainnet activity, and it did not report that the bridge flaw had been exploited, describing the change as preventive. Cross-chain bridges have been responsible for billions of dollars in cumulative losses through compromised keys, contract flaws and weak message verification, making the Pasteur checks a timely hardening step.
The upgrade follows the recent bridge-security episode on BNB Chain , underscoring how cross-chain infrastructure remains a top target.