Polygon Completes Hard Fork to Address Finality Issue

Polygon fixed a consensus bug with a hard fork after delays left transactions waiting up to 15 minutes for finality.

(AI-generated image)

Posted September 11, 2025 at 10:00 am ET.

Polygon rolled out a hard fork to fix a finality bug that was causing a 10 to 15-minute delay in transaction finality on its Polygon PoS network.

The bug originated from a misconfiguration in the consensus mechanism’s finality logic after a recent protocol upgrade, which extended the time transactions take to be confirmed irreversible.

Polygon first shipped hot fixes for the finality issue on its block production layer Bor and consensus layer Heimdall around five hours after identifying the problem.

This story is an excerpt from the Unchained Daily newsletter.

Subscribe here to get these updates in your email for free

The team implemented the hard fork at 11:00 am ET and said consensus finalization had been fully restored on Polygon PoS.

“The root cause today came from a faulty milestone proposal that pushed some Bor nodes onto divergent forks. This wasn’t accounted for, and it triggered short-term instability,” explained Polygon CEO Sandeep Nailwal.

“As we’ve seen before, there will be growing pains with any ambitious upgrade. But each one makes Polygon PoS stronger on our road to GigaGas throughput, making the chain more resilient for the long run.”