Flow Delays Restart as Rollback Plan Draws Bridge Objections

On December 28, 2025, the Flow Foundation delayed a planned network restart after its proposed recovery path—restoring the blockchain to a checkpoint before an exploit—drew objections from cross-chain bridge operators. The proposal would have excluded roughly six hours of transactions from the resumed ledger, according to contemporaneous reporting that cited Flow’s recovery announcement.

The dispute mattered beyond the approximately $3.9 million that Flow said had moved off-network. It exposed a harder coordination problem: a layer-one blockchain can change the history recognized by its own validators, but bridges, exchanges and custodians maintain separate records. Reversing one ledger after assets have crossed into another system can create conflicting balances and shift losses to parties that treated the original transactions as final.

From containment to a contested restart

Flow said an attacker exploited its execution layer on December 27, 2025, before validators coordinated a halt. In its contemporaneous incident update, the Foundation estimated that approximately $3.9 million had exited, primarily through bridges, and said existing user balances had not been accessed. It described containment as complete and said a protocol fix was in final validation.

An official node-operator notice likewise told operators to prepare for a full network upgrade, known in Flow terminology as a spork. Access nodes and EVM gateways were to shut down before the upgrade, with other node types instructed to stop at upgrade time. Flow Port and staking functions would remain unavailable until completion.

The recovery plan became contentious on December 28. The Block reported that Flow’s announcement called for restoration to a pre-exploit checkpoint and said transactions submitted during the affected window would not be retained and would need to be resubmitted. That was a proposed response, not a completed rollback.

Alex Smirnov, co-founder of bridge protocol deBridge, told The Block that his team had not received advance notice and argued that a rollback could harm users, liquidity providers and partners without recovering assets already moved beyond Flow. The report said deBridge and LayerZero favored a targeted hard fork that patched the vulnerability and confined implicated addresses instead of reversing the broader transaction window. Those were attributable stakeholder positions, not independently proven damage estimates.

Finality met off-chain accounting

The criticism focused on reconciliation. A centralized exchange may credit a deposit after observing a transaction on Flow; a bridge may mint or release an asset on another chain; a liquidity provider may trade against the resulting balance. If Flow later removes the source transaction while the external system retains its corresponding entry, both records cannot be honored without someone absorbing the difference.

Flow said on December 28 that it was extending the coordination window and, in a later update that day, carefully evaluating partner feedback while taking more time to seek broad support. The defensible event-day conclusion was therefore narrow: the network remained halted or restricted while the Foundation reconsidered how to restart it. No final recovery architecture had been executed on December 28.

The episode also illustrated the difference between validator coordination and ecosystem coordination. Validator agreement can authorize a chain upgrade. It cannot automatically update databases, risk controls or legal obligations at independent exchanges and bridge operators. That gap made the restart design an institutional question as well as a software patch.

Later context

Flow’s January 6, 2026 technical postmortem said the ecosystem ultimately selected an “Isolated Recovery Plan” instead of checkpoint restoration. It preserved legitimate transaction history while restricting incident-linked accounts, and Flow said the Cadence environment resumed read-write processing on December 29, 2025. Those outcomes clarify the December 28 debate; they were not yet established when the rollback proposal and objections were unfolding.