$BNB Chain has announced that it will activate its Pasteur hard fork on the mainnet $BNB Smart Chain (BSC) at 02:30 UTC on August 25, 2026.
The documentation indicated that every node operator must use client version 1.7.7 by this time, or risk being disconnected from the network.
$BNB Chain confirmed the date and client requirements in a blog post published on August 14.
Are the $BNB Chain Proposals Combined into One General Update?
The Pasteur hard fork is included in the BEP-673 meta-proposal. However, it also consolidates three other proposals, BEP-682, BEP-695, and BEP-675, into one coordinated activation.
BEP-682 and BEP-695 focus on operations to enhance the security of the bridge, staking, and governance. BEP-675 is a project aimed at increasing throughput, which technically does not require a hard fork to function.
$BNB Chain has also intentionally chosen names for its hard forks. They are dedicated to scientists, including Pascal, Maxwell, Fermi, and Mendel. Each hard fork introduced gradual changes to the blockchain.
The Fermi hard fork was launched in January 2026 and helped reduce block generation time on the BSC network to 0.45 seconds. Since then, the network has stabilized at this level and has not accelerated further.
Fixing a Vulnerability in the Bridge's Duplicate Verification System
The BEP-682 standard is designed to revise the method of verifying cross-chain transfers in the BSC system.
When assets move into the blockchain, BSC does not trust the originating blockchain's assertion on its own. Instead, it runs a precompiled contract at address 0x67, which counts validator signatures against a known set of validators. The transfer only proceeds after a supermajority has signed it.
However, this approach had its drawbacks, as there was no way to confirm that each validator appeared only once.
A specially crafted set of validators could list the same signer multiple times, count their voting power each time they appear, and overcome the threshold with fewer genuine signatures than the rule requires.
BEP-682 removes duplicates before counting, ensuring that redundant data sets can no longer exceed the threshold.
Ensuring Obsolete Validator Keys Are Truly Obsolete
The BEP-695 standard is designed to address a vulnerability in staking and governance systems. When validators change their consensus keys as part of scheduled maintenance, it is assumed that the retired key no longer holds any authority.
Previously, however, this was not entirely the case. Now, three fixes for this issue have been implemented across each $BNB Chain. The first is that an old, rotated key now loses its validator administrator rights rather than retaining them.
The second fix ensures that a validator can no longer avoid an upcoming eviction through rotation. It also blocked addresses on a blacklist from participating in signature-based governance voting.
Fuller Blocks Without Gas or Block Execution Time Constraints
Currently, blocks in BSC are executed twice. In the first execution, the proposer runs transactions to confirm block validity, and then the validator runs all those transactions again before signing.
However, this action again takes 450 milliseconds (ms), and the time the validator spends on the second run is time lost for proposers to package the next block.
The BEP-675 standard allows the proposer to pass along a block they have already executed.
This time, the validator checks it against consensus rules, signs it, relays the data, and then completes the full verification.
Data collected on the testnet showed that the time validators spent executing transactions dropped from 125 milliseconds to 15 milliseconds. Furthermore, throughput increased by nearly 88%—from 1,237 to 2,324 transactions per second (TPS)—while the 100 million gas limit and 450 ms interval remained unchanged.
The average gas used per block increased from 46.35 million to 84.15 million. Finalization latency remained unchanged. However, $BNB Chain emphasized that these are controlled load metrics. It will still have to withstand mainnet load, especially when multiple proposers compete for the same slot.
What Must Operators Do Before the 25th?
Node operators are the ones with future work on the Pasteur project. $BNB Chain has provided detailed documentation on what needs to be done to avoid launch errors.
Developers wishing to use the BEP-675 algorithm may need to put in extra effort, as it means running a full node instead of a light one, since the proposer now creates a fully executed block. Traditional mining schemes continue to work, simply with less packaging time.
