Polygon’s proof-of-stake (PoS) network has underwent an emergency hard fork on Wednesday after a software bug disrupted transaction finality, causing 10–15 minute delays in confirming blocks.
The Polygon Foundation confirmed that the upgrade, aimed at restoring the network’s “local fast finality,” was successfully completed and that transactions are once again processing normally.
“Checkpoints are going through and consensus finalization has been fully restored on Polygon PoS,” the team announced on X, adding that engineers will continue to monitor the network for stability.
What Happened
The issue surfaced when Polygon validators noticed that “milestones”, the internal markers that indicate irreversible state changes on the Layer-2 chain, were lagging behind schedule. Although Polygon continued to produce blocks and Ethereum mainnet checkpoints remained intact, the delay meant that transactions were not reaching finality as quickly as usual, leaving a brief window where blocks could theoretically be reorganized.
Polygon engineers deployed two critical upgrades to resolve the bug:
- Bor v2.2.11-beta2, the software that handles block production.
- Heimdall v0.3.1, the layer responsible for validator coordination and consensus.
The fixes were rolled out at 3 p.m. UTC, restoring normal confirmation times.
A Recurring Challenge
Polygon described the bug as a “local fast finality” issue, essentially a hiccup in the deterministic state of the Layer-2 network itself. Finality is a key security measure ensuring that once a transaction is validated, it cannot be reversed.
While the root cause of Wednesday’s glitch remains under investigation, the network faced a similar problem earlier this year, shortly after releasing Heimdall v2, its most complex hard fork since 2020.
Market Impact and Next Steps
During the disruption, POL, Polygon’s native token, briefly slipped about 4% before rebounding once finality was restored.
The Polygon team said it will continue to closely monitor the network to prevent further incidents and maintain validator synchronization.
The swift fix highlights both the complexity and resilience of Ethereum’s leading Layer-2 ecosystem: even as millions of transactions flow through Polygon daily, a coordinated validator response and rapid software patching kept the network online with minimal user disruption.
