BSC sets August 25 for Pasteur hardfork, orders nodes onto v1.7.7

BNB Chain has announced that it will activate its Pasteur hard fork on the BNB Smart Chain (BSC) mainnet at 02:30 UTC on August 25, 2026. 

It stated that every node operator has to be running client v1.7.7 before that time or risk falling off the network. 

BNB Chain confirmed the date and client requirement in a blog post that was published on August 14.

Are the BNB Chain proposals riding under one meta upgrade?

The Pasteur hardfork is placed under meta proposal BEP-673. However, it also brings three other proposals, BEP-682, BEP-695, and BEP-675, into one coordinated activation.

BEP-682 and BEP-695 are focused on security work on the bridge, the staking and governance contracts. BEP-675 is a throughput play that does not technically need a hardfork to function.

BNB Chain has also been intentional in its naming of the hardforks that it has launched. They have been themed after scientists, which include Pascal, Maxwell, Fermi, and Mendel. Each one of the hardforks has added incremental changes to the chain. 

The Fermi hardfork was shipped in January 2026 and helped cut BSC’s block times to 0.45 seconds. The network has spent the months since steadying itself at that pace rather than pushing it faster.

Closing a duplicate-validator loophole in the bridge

BEP-682 is designed to rewrite how BSC checks cross-chain transfers.

When assets move onto the chain, BSC does not trust the origin chain’s claim on its own. What it does instead is to run a precompile at address 0x67 that counts validator signatures against a known validator set. The transfer only goes through once a supermajority has signed.

However, this had its flaws, as there was no way to confirm that each validator only showed up once.

A crafted validator set could list the same signer several times, count that signer’s voting power on every appearance, and clear the threshold with fewer genuine signatures than the rule demands. 

BEP-682 takes out duplicates before the count, and this ensures that inflated sets no longer clear the bar. 

Making retired validator keys actually retire

BEP-695 is designed to handle a weakness in staking and governance. When validators rotate their consensus keys as routine maintenance, the assumption is that a retired key stops carrying any authority.

However, that was not exactly how it behaved before. There are now three fixes to the issue per BNB Chain. The first one is that a rotated old key now loses its validator-admin privileges instead of keeping them. 

The second fix ensures that a validator can no longer avoid a pending eviction by rotating. It also blocked blacklisted addresses from signature-based governance votes. 

Fuller blocks without touching gas or block time

Currently, blocks get executed twice on BSC. The first execution has the builder running the transactions to confirm the block is valid, and then the validator runs all of them again before signing.

However, that action again eats into a 450-millisecond (ms) window, and the time the validator spends running the second execution is time builders lose to pack the next block.

BEP-675 allows a builder to hand over a block that it has already executed. 

This time around, the validator checks it against consensus rules, signs, broadcasts, and then finishes full verification afterward. 

The data gathered from the testnet showed that the time validators contribute to the execution layer was reduced from 125 milliseconds to 15 milliseconds. Also, the throughput rose by nearly 88% from 1,237 to 2,324 transactions per second (TPS), with the 100 million gas limit and 450 ms interval left untouched. 

The average block gas used rose from 46.35 million to 84.15 million. Finality lag held steady. However, BNB Chain highlighted that those are controlled-workload figures. It will still need to hold up under mainnet traffic, especially when several builders bid for the same slot.

What do operators have to do before the 25th?

Node operators are the ones with a bucket list of things to do with Pasteur coming up. BNB Chain has provided extensive documentation of what one needs to do to avoid startup errors. 

Builders who want the BEP-675 path may have to put in extra work, as it means running a full node instead of a fast node since the builder now produces a fully executed block. Legacy bids keep working, just with less packing time.