Base pushed a required upgrade. It quietly patches a bug that was giving live apps wrong block data.
Base patched a live bug alongside a required hardfork upgrade, and the bug is the more important of the two.
CryptoVibe Desk · base · node-upgrade · flashblock
- →Base shipped v1.1.1 on June 19, requiring all mainnet node operators to upgrade by June 25 at 18:00 UTC before the Beryl hardfork.
- →A Flashblock bug meant BLOCKHASH returned different values during pre-confirmation than on the final chain, a silent correctness risk for any dependent contract or bot.
- →Watch for incident reports from dApps or MEV strategies that were calling BLOCKHASH during Flashblock pre-confirmation before this patch, reported before or just after the June 25 deadline.
- Hardfork → A required software update that changes how a blockchain processes transactions; nodes that skip the upgrade stop working with the rest of the network after the deadline.
- BLOCKHASH opcode → An instruction inside a smart contract that reads a recent block's unique identifier, most commonly used as a randomness source or for timing logic.
- Flashblock pre-confirmation → A Base feature that gives apps a fast preview of transaction outcomes before the block is fully finalized; the bug meant this preview could show a different value than the final chain eventually committed.
- Canonical chain → The official, agreed-upon record of blockchain history that all nodes accept as final truth once a block is confirmed.
Base shipped v1.1.1 today, per the release notes on GitHub. All mainnet node operators must upgrade by June 25 at 18:00 UTC.
The Beryl hardfork deadline is the visible story. And that's the catch: the bug fix is the more important part.
v1.1.1 patches a Flashblock BLOCKHASH divergence. When a transaction called the BLOCKHASH opcode during Flashblock pre-confirmation, it could return a different value than what the canonical chain eventually committed. That's a live correctness risk, not a theoretical one. Any contract or MEV bot reading BLOCKHASH inside a Flashblock window was working from data that might not match the final chain.
The mismatch matters because contracts use BLOCKHASH as a pseudo-random input or for timing checks. If the pre-confirmation value and the canonical value differ, execution logic built on that value can produce different outcomes. What your contract acted on might not match what landed on chain.
Base ran the standard two-phase rollout. v1.1.0 shipped June 12 for Sepolia testnet with a June 18 deadline. v1.1.1 is the mainnet follow-on.
If you run a Base node, upgrade before June 25. If you're writing contracts that call BLOCKHASH, check whether your execution path runs inside a Flashblock window.
Base shipping Flashblock without explicit BLOCKHASH semantics documentation was a correctness trap for every developer who trusted the feature announcement over the node source.
A post-mortem or on-chain anomaly from any BLOCKHASH-dependent contract or MEV strategy active during Flashblock pre-confirmation before the v1.1.1 patch, reported before or just after the June 25 upgrade deadline.
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