Network Incident History

A running log of substantive incidents and scheduled upgrades affecting Base Mainnet and Base Sepolia. Procedural status pings are omitted. Entries are newest first.

2026

2026-10-08 — mainnet.base.org loses debug, trace, and txpool (scheduled)

From Thursday, October 8th at 12:00 UTC, the free public endpoint https://mainnet.base.org stops answering the debug, trace, and txpool namespaces. Reads that remain get a tighter rate limit. The endpoint stays free and best-effort for basic reads. The notice went up on October 1 and gives a window that ends October 9 at 12:00 UTC. Any app that calls those namespaces on the public host, or needs more throughput than the new limit allows, must move to a dedicated node provider before the 8th.

2026-10-05 — V1 node snapshots retired (completed)

From Monday, October 5th at 12:00 UTC, Base stopped publishing V1 node database snapshots and stopped serving the ones already out there. The notice went up on September 29 with a 24-hour window ending October 6 at 12:00 UTC. The status page marked the work complete on October 6 at 14:00 UTC, two hours past that window. Operators who still restore from V1 need to move to the V2 snapshots at chain.base.org/snapshots; see Snapshots for the restore steps.

2026-09-30 — Mainnet Cobalt upgrade (completed)

The window opened on schedule at 18:00 UTC and closed as complete at 20:00 UTC. No incident was raised against it.

Base Mainnet was scheduled to activate the Cobalt hardfork on Wednesday, September 30th at 18:00 UTC (Unix timestamp 1790791200), with a maintenance window running until 20:00 UTC. The notice went up on September 23 at 23:00 UTC, a few hours after the Sepolia window closed. Mainnet operators must run v1.4.2 of github.com/base/base or a later release. That is a higher floor than the compiled-in timestamp alone implies: v1.4.1 already carries the Mainnet value, but v1.4.2 adds a backport (#5260) that registers the validity transaction RPC ahead of Cobalt and switches it on from the live upgrade schedule. Details are in the Cobalt Upgrade Overview.

2026-09-23 — Sepolia Cobalt upgrade (completed)

The maintenance window opened on time at 18:00 UTC and was marked complete at 20:00 UTC, with no incident reported against it.

Base Sepolia is scheduled to activate the Cobalt hardfork on Wednesday, September 23rd at 18:00 UTC (Unix timestamp 1790186400), with a maintenance window held open until 20:00 UTC. Operators of Sepolia nodes must be running the v1.4.0 release of github.com/base/base or later; earlier builds have no Cobalt timestamp compiled in and will not follow the fork. That floor applies to Sepolia only. The Mainnet activation timestamp was not added to the source until 2026-09-21, after v1.4.0 was tagged, so Mainnet operators need a later build for their own September 30 window. The notice also restates where node software now comes from: github.com/base/base publishes the public node that used to ship from base/node. Scope and migration notes are in the Cobalt Upgrade Overview.

2026-07-28 — Mainnet safe head fell behind

At 13:10 UTC on Tuesday, July 28th, the safe head on Base Mainnet was reported as lagging. Unsafe block production was unaffected — the delay was confined to the batching of L2 data down to Ethereum L1, so chain progress at the tip continued as normal. The safe head was advancing again by 15:13 UTC, when the incident was closed.

2026-07-21 — Mainnet Flashblocks websocket capacity reduced

On Tuesday, July 21st, the Flashblocks websocket stream on Base Mainnet ran at reduced capacity for roughly fifty minutes, spanning 19:50 to 20:42 UTC. Subscribers were likely to see messages arrive late over that window, and fresh connection attempts could come back rate limited. The event was marked resolved once stream capacity recovered.

2026-06-25 — Mainnet chain stall

Beginning at 16:03 UTC on Thursday, June 25th, Base Mainnet block production turned unhealthy. The team traced it to a consensus fault: an invalid block had been sequenced, which kept new blocks from being built past block 47806542. Sequencing of fresh blocks was restored by around 17:51 UTC, though ecosystem node operators had to restart their Base nodes to resume syncing. Healthy block building was confirmed shortly after, and the Beryl hardfork still activated on schedule at 18:00 UTC. By 19:22 UTC the network was stable with recovery verified across the ecosystem; any nodes still stuck at block 47806542 recover on restart. The root cause was identified and a fix put under verification, with a full post-mortem and root-cause analysis promised to the ecosystem.

2026-06-25 — Mainnet Beryl upgrade (scheduled)

Base Mainnet is scheduled to activate the Beryl hardfork on Thursday, June 25th at 18:00 UTC (Unix timestamp 1782410400). Operators of Mainnet nodes must move to the 1.1.1 release or later of github.com/base/base, with matching preconfigured binaries published as the v1.1.1 release of github.com/base/node. Migration steps are documented in the Beryl Upgrade Overview.

2026-06-18 — Sepolia Beryl upgrade (scheduled)

Base Sepolia is scheduled to activate the Beryl hardfork on Thursday, June 18th at 18:00 UTC (1781805600). Operators of Sepolia nodes need to move to the v1.1.0 release or later of github.com/base/base, with matching preconfigured builds shipped as the v1.1.0 release of github.com/base/node. The migration details live in the Beryl Upgrade Overview.

2026-06-12 — Mainnet p2p peering instability

On Friday, June 12th at 21:28 UTC, the team began investigating peering problems on Base Mainnet where newly started nodes were having trouble finding peers. As a temporary measure, affected operators were pointed at a short list of --trusted-peers enode entries to add to their Reth node and restart while a fix was developed.

2026-06-02 — Mainnet Flashblocks broadcasting degraded

On Tuesday, June 2nd at 22:32 UTC, the team began investigating periodic instability in Flashblocks broadcasting on Base Mainnet. Pre-confirmation delivery was affected, but transaction inclusion in sealed blocks was reported as unaffected throughout.

2026-05-29 — Mainnet withdrawal delay (TEE enclave)

On Friday, May 29th at 15:55 UTC, Base Mainnet withdrawals began running late after a TEE enclave fault stopped output proposals from being posted. The issue was identified and a fix was reported in progress; withdrawals resume once proposals catch back up.

2026-05-28 — Mainnet Azul upgrade (scheduled)

Base Mainnet activates the Azul hardfork on Thursday, May 28th at 18:00 UTC. Node operators must run version 0.9.0 or later of github.com/base/base, with corresponding preconfigured binaries published as the v0.16.0 release of github.com/base/node. From this upgrade onward, base-consensus and base-reth-node are the only supported clients — op-node and op-geth will not follow the new chain. Pending withdrawals will be invalidated by the upgrade; users with in-flight withdrawals will need to submit a second proof transaction afterward to complete them. Migration steps are documented in Base v1 upgrade.