Base Activates Cobalt Upgrade

It's Wednesday, September 30, 2026.

Base activated its Cobalt upgrade on mainnet. Glamsterdam client releases are ready for Sepolia ahead of the October 6 activation. And Ostium opened a limited recovery program after a $23.75 million hack.

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Base Activates Cobalt Upgrade

Base activated its Cobalt network upgrade on mainnet, introducing Validity Transactions, a new transaction format that allows users to attach conditions to signed transactions. Transactions remain private and dormant until those conditions make them eligible for inclusion; Base does not choose the transaction or set its eligibility criteria. Cobalt marks Base's third standalone network upgrade.

Cobalt also adds three B20 features: Composite Policies combine existing allowlists and blocklists using AND or OR logic; scheduled multiplier updates, aligned with ERC-8056, support corporate actions without changing raw balances or transfer behavior; and seizeWithMemo lets authorized issuers reassign balances with an onchain memo when seizure is enabled for the token. Base’s next upgrade includes plans for 200ms blocks, Base Transactions, and DevX support for some Glamsterdam EVM improvements.

Glamsterdam Testnet Client Releases

Glamsterdam-ready client releases are now available for the Sepolia testnet, ahead of the scheduled activation on October 6, 2026, at 13:53:36 UTC (epoch 353,024, slot 11,296,768). Testnet node operators must update both execution and consensus clients before the scheduled fork activation. Node operators should also review new instructions for ePBS and builder tooling.

Prysm and Teku will default to a 60M gas limit post-activation, and operators seeking the full 200M limit must manually configure it per their specific client release notes. Glamsterdam will bring enshrined proposer-builder separation (ePBS) and block-level access lists for parallel state reading. Hoodi and mainnet activation dates will be determined in the coming weeks.

Ostium Releases Recovery Portal

Ostium launched a recovery portal for holders affected by its July 15 hack, which drained approximately $23.75 million from the protocol's OLP holders. The plan offers affected holders with a loss of $1,000 or less to claim an equal amount in USDC, which accounts for 3,321 of 3,666 affected wallets. The compensation must be claimed within 90 days. The plan also offers OLP holders with losses exceeding $1,000 a max compensation of $1,000

The proposed compensation amounts to a small fraction of total user losses in dollar terms. OLP holders with losses exceeding $1,000 also have the option to participate in an uncertain Stage 2 pro-rata recovery and have 30 days to choose to either accept a $1,000 payment or participate in an uncertain Stage 2 pro-rata recovery, which will allocate unclaimed funds and future protocol revenue to the recovery.

Misc News

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Zip allows you to deposit private ETH from Ethereum L1 into ZK Money. Aave proposes to support the OUSD stablecoin. CoW Swap opens TWAP orders for all users.

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