We are excited to share the highlights of the upcoming v1.8 upgrade for Cronos EVM mainnet, scheduled to go live on October 22, 2026.
This upgrade delivers smarter transaction handling, mature parallel EVM execution, major framework upgrades, the Ethereum Osaka hardfork, over 40 bug fixes, and pushes Cronos’s Ethereum API compatibility above 90%.
Application-Side Mempool
Until now, the pool of pending transactions was managed by CometBFT (the consensus layer). In v1.8, Cronos introduces the option for the application layer itself to take over mempool management.
This is significant because it changes how transactions are validated before they enter a block:
Customizable validation: The app-side mempool allows Cronos to customize its transaction verification logic, enabling more flexible validation before block construction.
Faster block production: As customization is possible, redundant verification steps can be removed, speeding up both transaction admission and post-block revalidation. Additionally, post-block revalidation also now runs asynchronously in the background, instead of competing with consensus and block production.
Less redundant work: Transaction admission and block construction share more processing, reducing the total compute cost per transaction.
The app-side mempool is opt-in. Existing node configurations continue to work without changes. Node operators who want to enable it can refer to the migration guide for detailed setup instructions.
Parallel EVM Execution
The Block-STM parallel execution engine, first introduced in earlier Cronos releases, has reached full maturity in v1.8. It is now directly embedded within the Cosmos SDK layer, enabling high-concurrency smart contract execution.
Block-STM processes multiple transactions within a block simultaneously. When transactions don’t conflict with each other, which is the common case, they execute in parallel, delivering higher throughput. When conflicts are detected, the engine automatically falls back to sequential re-execution for the affected transactions.
This is recommended for all node types, validators, RPC nodes, and archive nodes alike, and delivers the best block-execution performance available on Cronos.
EVM API Equivalence Above 90%
Cronos now supports over 80 individual Ethereum API methods, pushing EVM API equivalence above 90%. This means Ethereum-native developer tooling - wallets, block explorers, indexers, and development frameworks, which should work with Cronos with minimal or no modifications. This is an ongoing effort, and the Cronos team continues to close the remaining gaps to reach full parity.
Osaka Hardfork via go-ethereum v1.16.9
The underlying EVM engine has been upgraded to go-ethereum v1.16.9, which officially enables the Osaka hardfork on Cronos. This keeps Cronos aligned with Ethereum’s latest execution-layer changes.
Experimental: libp2p Networking Support
v1.8 ships with experimental support for libp2p as an alternative networking stack, aimed at reducing peer-to-peer latency and improving network resilience. The integration is complete, but it is not yet enabled on mainnet. This will be one of the key focuses following this upgrade.
Core Framework Upgrades
All major dependencies have been upgraded to their latest versions:
Cosmos SDK: upgraded to v0.54.3, bringing performance improvements and new features across the application framework.
IBC-Go: upgraded to v11, with the latest cross-chain interoperability improvements.
CometBFT: upgraded to v0.39, the latest consensus engine release.
RocksDB: upgraded to v10.9.1, with new experimental tuning profiles that allow node operators to optimize storage performance based on their node’s role (validator, RPC, or archive).
Additionally, the staking end-block queue has been optimized by replacing iterator-based processing with pending queue slots, reducing computational overhead during end-of-block processing.
Bug Fixes and Security Improvements
v1.8 includes over 40 bug fixes that improve long-term state stability and prevent regressions. The most notable:
Token mapping hardened: Token-mapping proposals now require valid contract code. Auto-mapping on denom remaps has been retired. Source denom mapping is now immutable once set. CRC21 token-mapping registrations targeting the zero address or the Ethereum precompile address range are rejected.
EVM correctness: A minimum gas cost is now enforced for calldata-heavy transactions (floor-data-gas). EIP-1559 balance checks are now enforced during block execution, not just during transaction checking, closing a gap where these checks were previously skipped outside of transaction checking.
Access control: SendCroToIbc is now restricted to authorized contracts only. Message count and per-message gas are bounded in the ReplayBlock gRPC query.
Infrastructure: IBC callback responses have been fixed. The restore-versiondb CLI command now correctly ignores non-leaf node data. Unused precompiles have been removed.
Breaking Changes
Validators and node operators should be aware of the following changes that take effect at the upgrade height:
SendCroToIbc is now restricted to authorized contracts. Contracts that currently use the CRO-to-IBC hook should verify they are on the authorized list.
Interchain Accounts (ICA) have been removed. ICA users and ICA precompile callers will be affected.
MsgTurnBridge is no longer supported.
A minimum gas cost is now enforced for calldata-heavy transactions, which may affect dApps that send large calldata payloads.
Governance parameter bounds have been tightened, which may affect governance proposers.
The json-rpc.txfee-cap setting is now enforced on eth_sendRawTransaction. Node operators serving JSON-RPC should review and adjust this value before the upgrade. See the migration guide for recommended settings.
What’s Next
For node operators looking to prepare, the full v1.8 migration guide includes upgrade procedures, recommended configurations for validators, RPC nodes, and archive nodes, and detailed explanations of all new configuration options:
Release note: https://github.com/crypto-org-chain/cronos/releases/tag/v1.8.0
Full Changelog: https://github.com/crypto-org-chain/cronos/releases
v1.8.0 Release & Migration Guide:
https://github.com/crypto-org-chain/cronos/releases/tag/v1.8.0
Cronos team will continue building toward faster, more compatible, and more resilient infrastructure for the Cronos ecosystem. Stay tuned for more updates.