Polygon Labs Issues Urgent Client Upgrade Notice After Hardforks

Polygon Labs has issued an urgent client upgrade notice following two recent hardforks, Austin and Kyoto. The company stated that any Polygon PoS node that remained on pre-hardfork Bor or Heimdall binaries past two specific August activation heights has fallen out of canonical consensus.

In practice, the stale node must upgrade and catch up before it can follow the network's accepted history again. This affects nodes running versions earlier than v2.10.0 for Bor and v0.11.0 for Heimdall, which are incompatible after Austin activated at mainnet block 91,949,700 and Kyoto at height 51,533,000 respectively.

Austin addressed two separate client risks: capping gas consumed while processing state-sync events from L1-to-L2 bridge deposits, and removing the TxDependency extra-data field to prevent resource-exhaustion risks. Meanwhile, Kyoto's highest-severity fix targets deeply nested google.protobuf.Any messages, adding a byte-level nesting check at both mempool admission and block-proposal processing.

Both hardforks are plain binary upgrades with no state migration or genesis change, and nodes that had not diverged require no resync. Operators already past the relevant height on an older client should install the applicable release, roll back to a pre-hardfork point if needed, and resync under Polygon's guidance.