Shardeum Proposes v1.1.0 Mainnet Upgrade to Cosmos EVM v0.6.3

Shardeum has submitted Proposal #1, a governance proposal for a coordinated mainnet upgrade to Shardeum v1.1.0, which resynchronizes Shardeum EVM with Cosmos EVM v0.6.3.

The proposed upgrade incorporates upstream Cosmos EVM changes, security fixes carried forward from Shardeum v1.0.2, and the state migration required for Shardeum’s existing mainnet state.

If approved by governance, Shardeum mainnet will upgrade at block height 7,927,860, currently estimated for October 13, 2026 at 06:00 UTC.

Validators and other node operators will need to prepare for the v1.1.0 upgrade in advance and switch to the new binary at the specified upgrade height.

Proposed Upgrade Timeline

Milestone	Details
Governance Proposal	#1
Governance voting begins	October 6, 2026 at 10:30 UTC
Upgrade instructions to be published	October 8, 2026*
Governance voting ends	October 9, 2026 at 10:30 UTC
Upgrade binary distributed to validators/infrastructure providers	October 9 – 11, 2026*
Recommended CEX deposit/withdrawal suspension	October 13, 2026 at 02:00 UTC*
Proposed mainnet upgrade	October 13, 2026 at approximately 06:00 UTC*
Upgrade block height	7,927,860

*Timing may change based on final technical readiness, network conditions, and coordination. Milestones, especially after October 9, are contingent on Proposal #1 passing.

Who can vote

Validators and SHM holders with bonded stake delegated to an active validator can vote on Proposal #1. No deposit is required to cast a vote.

If you are a delegator and do not vote, your delegated stake will follow your validator’s vote, if the validator votes. You can override your validator’s vote by casting your own vote at any time during the voting period.

Details of the Proposed Upgrade

What Does the Upgrade Change?

The Shardeum v1.1.0 release includes:

• Resynchronization of Shardeum EVM with upstream Cosmos EVM v0.6.3
• Security fixes previously included in Shardeum v1.0.2, carried forward into the v1.1.0 release

This means the upgrade involves both deploying updated node software and applying the corresponding state migration required for the existing Shardeum mainnet.

Why Is a Coordinated Network Upgrade Required?

Cosmos EVM v0.6.3 includes state-breaking changes, which means validators cannot independently switch to the new software while the network continues operating normally.

Instead, Shardeum will use the standard Cosmos software-upgrade process.

If Proposal #1 passes, the upgrade will take place at block height 7,927,860. When the network reaches that height, nodes running the existing software will halt as expected. Validators will then restart their nodes using the Shardeum v1.1.0 binary containing the upgrade logic required for the new network state.

Once sufficient validator voting power is online with the upgraded software and consensus resumes, the network will continue producing blocks under the updated software. Because the upgrade is triggered by block height rather than a fixed clock time, the exact time at which the network reaches the upgrade height may vary.

What Do Validators Need to Do?

1. Prepare the Shardeum v1.1.0 upgrade before the upgrade height.
2. Keep running the current mainnet release until the upgrade height is reached.
3. Do not switch to the new binary early unless Shardeum instructs otherwise.

GitHub release: Shardeum v1.1.0

Note: Upgrade instructions are expected to be published on October 8. If Proposal #1 passes, the final upgrade binary will be shared with validators and other infrastructure providers between October 9 and 11.

These dates may change, so operators should monitor Shardeum’s official validator channels including Discord for final instructions and coordination updates.

What About Full Nodes and RPC Nodes?

Full-node and RPC-node operators must also upgrade to a compatible release.

Nodes that continue running the previous software after the network upgrade will no longer be able to correctly follow the upgraded Shardeum mainnet. Operators should therefore stage the compatible release ahead of the upgrade and switch to it once the scheduled upgrade height is reached.

Updated node upgrade instructions are expected to be published on October 8 for validators, full nodes, and RPC nodes in the respective Shardeum docs pages.

Information for Exchanges and Infrastructure Providers

Exchanges, RPC providers, indexers, custodians, bridges, and other infrastructure operators running Shardeum nodes should prepare for the upgrade in advance.

Shardeum recommends that exchanges temporarily suspend SHM deposits and withdrawals beginning approximately at 02:00 UTC on October 13, 2026, ahead of the scheduled network upgrade.

Deposits and withdrawals should resume only after:

• Their Shardeum node has been upgraded
• The node is fully synced with mainnet
• Normal network operation has been confirmed

Additional coordination details will be shared directly with infrastructure partners ahead of the upgrade.

What Does This Mean for Shardeum Users?

Regular Shardeum users do not need to take any action for the software upgrade.

When Shardeum reaches the scheduled upgrade height, the network will temporarily halt as part of the planned upgrade process while validators transition to the new software. During this period, transactions and applications using Shardeum will temporarily be unavailable.

The upgrade is currently estimated to begin around October 13, 2026 at 06:00 UTC. Once sufficient validator voting power is online with the upgraded software and consensus resumes, the network will begin producing blocks again. Network operations are expected to resume later the same day, subject to the upgrade progressing as planned.

Shardeum will confirm once the upgrade has been successfully completed and normal network operations have resumed.