Polygon Labs Warns Old Polygon PoS Nodes Fell Out of Consensus After Austin and Kyoto Forks

Polygon Labs issued an urgent notice after the Austin and Kyoto hard forks activated on Polygon PoS. According to ChainCatcher, nodes still running older Bor or Heimdall versions have fallen out of consensus and must upgrade to catch up with the network. Austin activated at mainnet block 91,949,700 and requires Bor v2.1.0 or later. Kyoto activated at block 51,533,000 and requires Heimdall v0.11.0 or later. Austin addresses two Bor resource-exhaustion risks: L1-to-L2 bridge state-sync events not being counted toward the gas limit could slow block processing, and an unlimited TxDependency field could cause peer nodes to crash. Kyoto fixes vulnerabilities involving deeply nested message attacks, fee-token scanning, and checkpoint signature recovery. Both hard forks are binary-only upgrades with no state migration, and nodes that did not fork do not need to resynchronize. Operators of older clients should upgrade and, if necessary, recover synchronization under Polygon guidance.