Pasteur Hard Fork Activation Date and Mandatory Upgrade
BNB Chain is set to activate the Pasteur hard fork on BNB Smart Chain at 02:30 UTC on August 25, 2026, as reported by Crypto News. The upgrade is mandatory and introduces three proposals: BEP-682, BEP-695, and BEP-675. All BSC mainnet nodes must run client version 1.7.7 before activation, according to the official release. Regular users and most application developers do not need to migrate funds or change their software.
Security Enhancements: Bridge Verification and Validator Key Rotation
BEP-682 changes how BSC validates blocks used for cross-chain transfers. The network now checks validator signatures before accepting information from another chain, ensuring that the required voting threshold approved the block. The previous process did not confirm that every validator appeared only once in a submitted validator set, allowing a specially constructed set to potentially repeat a validator and count its voting power more than once. BEP-682 rejects duplicate entries, making the threshold reflect a genuine validator supermajority.
BEP-695 addresses validator key rotation. After Pasteur, an old consensus key will lose its administrative authority instead of retaining privileges following a rotation. Pending slash evictions will follow validators to their new keys, preventing a validator from avoiding an outstanding eviction by changing keys. The proposal also blocks blacklisted addresses from using signature-based governance voting methods to bypass restrictions applied to direct votes. These measures affect BSC staking and governance system contracts, but BNB Chain says developers do not need to migrate existing applications because the changes occur at the protocol and system-contract levels.
BEP-675: Increasing Block Capacity
BEP-675 allows builders to submit blocks they have already executed. Validators check, sign, and broadcast the block, then complete full verification outside the critical path. On the QANet test environment, processing within the critical path fell from 125 milliseconds to 15 milliseconds, and average block gas use increased from 46.35 million to 84.15 million against the 100 million limit. Throughput on QANet rose from 1,237 to 2,324 transactions per second during tests, while the block interval remained at 450 milliseconds and finality lag did not change. BNB Chain cautioned that these figures came from controlled testing rather than live mainnet activity.
Builders adopting the new path must operate full nodes because they will produce fully executed blocks. Legacy block bids will remain available, although they provide builders with less time to fill blocks.
Node Operator Requirements
Node operators must remove [Eth] EnableBAL from config.toml; otherwise, the updated client will fail to start. The release also recommends removing [TxPool] OverflowPoolSlots, although the client will silently ignore that field. Several command-line flags are obsolete or inactive, including --journalfile, --enablebal, and --txpool.overflowpoolslots.
Context: From Speed to Fuller Blocks
The Pasteur hard fork takes a slight turn from the last two upgrades, which were about speed. The Fermi hard fork, which activated in January this year, brought block times down to 0.45 seconds, and was followed by the Osaka/Mendel hard fork in April, which steadied the network at that pace. BNB Chain developers note that Pasteur is about using that speed more fully and closing two ways a validator could hold onto power it should not have, with three proposals shipped in the fork, grouped under BEP-673.
Testnet and Roadmap
The Pasteur hard fork has been live on the BSC testnet since July 21. No comparable mainnet performance increase has been confirmed yet. BEP-675 is the capacity workstream in the H2 2026 roadmap. In the first half of 2026, BSC cut block intervals to 450 ms, brought in-memory finality down to 650 ms, and nearly doubled benchmark throughput to about 5,200 TPS. The H2 objective is to double mainnet throughput again, on a stated path toward a 10x improvement across BNB Chain.
Community Countdown
The BNB Chain community is counting down with two days left until the Pasteur hard fork, as reported by u.today. In a recent post, BNB Chain launched a countdown, listing major upgrades including stronger bridge verification, safer validator key rotation, and more room in every block. A tweet from BNB Chain read: "3 days until Pasteur Hardfork. Heavy upgrades are coming: → Stronger bridge verification → Safer validator key rotation → More room in every block Node operators, upgrade to v1.7.7 before August 25."