Base Network Outage Halts Blocks After Sequencer Bug

The last block landed at 15:47:11 UTC, according to BaseScan. Base then confirmed unhealthy block production in a status update at 16:03 UTC. As of the 17:21 UTC update, the incident was still unresolved.

What Happened During the Base Network Outage

Block 47806542 carried 210 transactions, and then the chain went quiet. No new blocks followed it on BaseScan as of roughly 17:35 UTC. So transactions stopped clearing and the network effectively stalled.

The official Base status page tracked the incident in real time. The first alert came at 16:03 UTC. Updates then followed at 16:24, 16:52, and 17:21 UTC.

Meanwhile, the gap showed up on Ethereum too. The Coinbase-managed batch sender at 0x5050f69a…5b76c9 stopped posting new batches during the stall. As a result, fresh Base data never reached the L1 settlement layer.

By 17:08 UTC, Watcher.Guru reported that Base had been down for over an hour. Coinbase’s own status page also referenced the block production outage.

A Consensus Bug Sequenced an Invalid Block

According to Base, the root cause was a consensus problem. The sequencer produced an invalid block right after 47806542. That bad block then blocked the network from building any further blocks.

The team isolated the issue by the 17:21 UTC update. Internal sequencer and node software had preliminarily recovered at that point. Still, engineers were working to resume block propagation across the wider network.

The exact trigger behind the invalid block remained unconfirmed. Base did not specify whether load, a software bug, or another factor caused the consensus failure. So that detail is still open as the team continues its investigation.

Why One Sequencer Can Stall the Whole Network

Base is an optimistic rollup built on the OP Stack, the same framework behind Optimism. Coinbase launched it in August 2023. Like most major rollups, it runs a single centralized sequencer.

That sequencer orders transactions and produces L2 blocks roughly every two seconds. It then posts compressed batches and state roots to Ethereum for data availability and finality. The design is fast and cheap, yet it carries one clear trade-off.

A single-sequencer setup means the entire L2 halts if that sequencer fails. There is no automatic failover that kicked in here. L2BEAT flags this exact centralization risk in its Base risk metrics.

This was not the first such stall either. Base suffered a roughly 33-minute halt on August 5, 2025, after a faulty sequencer handoff during heavy activity. Coinbase published a postmortem then, and the same centralization questions resurfaced.

Are Funds Safe During the Base Network Outage?

User funds were not at risk of loss during the network outage. The L2 state was preserved, and Ethereum kept running normally underneath it. So balances stayed intact even while blocks stopped.

Deposits saw a major outage and withdrawals a partial one. Still, optimistic rollups include an L1 escape hatch. Users can prove their state on Ethereum and exit directly, though that path is slower and more expensive during an incident.

In practice, “down” here meant frozen activity rather than lost money. RPC calls could fail or lag. DEX volume on Base would also drop toward zero while the chain sat idle. None of that, however, threatened the underlying assets.

Community Renews Centralization Criticism

On X, the dominant reaction was frustration. Many replies revived the familiar line that centralized L2s carry a single point of failure. Some users joked that Base went from “build on Base” to “take a break on Base.”

The criticism largely amplified the official technical framing rather than contradicting it. No founder or analyst publicly disputed the status page account. As of the latest checks, Jesse Pollak, Coinbase, and the official Base accounts had not posted about the specific incident.

So far, no major outlet such as CoinDesk or The Block had published on this event. That is typical for a breaking, still-developing outage. The status page remained the only authoritative source on the cause and timeline.

What Comes Next

For now, the priority is restoring normal block propagation and clearing the backlog. A full postmortem will likely follow, as it did after the August 2025 stall. That report should detail the exact consensus fault.

The incident also reopens a broader question about rollup decentralization. Coinbase and other teams have outlined plans to decentralize sequencers over time. Events like this Base network outage tend to push that roadmap up the priority list.

Readers can track recovery directly on the status page and on BaseScan. This article reflects the situation as of 17:38 UTC on June 25, 2026, and may update as Base confirms a fix. None of this is financial advice.