Ethereum's Glamsterdam upgrade confirmed to activate on Sepolia on October 6, introducing ePBS and block-level access lists.

According to TechFlow, on September 29, as per the official announcement from the Ethereum Foundation, the Ethereum Glamsterdam network upgrade has been confirmed to activate on the Sepolia testnet at 13:53:36 UTC on October 6, 2026 (Epoch 353,024), with activation times for Hoodi and the mainnet remaining TBD.

Glamsterdam combines the Amsterdam execution layer and Gloas consensus layer upgrades, with core changes including the introduction of embedded Proposer-Builder Separation (ePBS, EIP-7732), which incorporates the block construction process into the consensus protocol and reduces reliance on middleware; the addition of Block Access Lists (BALs, EIP-7928), enabling clients to read state and verify transactions in parallel to boost execution throughput. Additionally, the upgrade adjusts the gas pricing mechanism (EIP-8037/8038) to more accurately reflect the actual costs of state creation and access, requiring application developers to test their contracts to adapt to the new rules.

Client versions currently confirmed to support the Sepolia activation include: Consensus layer – Lodestar 1.49.0, Prysm 7.2.0, Teku 26.9.1; Execution layer – Besu 26.9.0, Erigon 3.7.0, go-ethereum 1.17.6, Nethermind 2.0.0, Reth 2.7.0. Node operators must update both execution and consensus layer clients before activation.