Polygon Resolves Critical Bug With Emergency Hard Fork
On September 10, users and developers on the Polygon Proof-of-Stake (PoS) chain began reporting severe delays in transaction processing. What would normally take seconds was suddenly taking 10 to 15 minutes, creating panic and uncertainty across the ecosystem.
UPDATE: Temporary Delay in Finality
While the chain continues to run and blocks and checkpoints are produced, there is currently a 10-15 minute delay in finality due to a milestone issue.
We have identified a fix, and it is being rolled out to all validators and service…
— Polygon Foundation (@0xPolygonFdn) September 10, 2025
“Earlier today, Polygon PoS experienced a disruption where checkpoint finality on Ethereum was still active, but local fast finality on the chain (i.e. milestones) were delayed,” Sandeep Nailwal, Founder and CEO of Polygon, stated in a post on X.
The issue was traced to a critical bug in the network’s node software that disrupted the delicate synchronization between validators.
Polygon’s Technical Response
The Polygon Foundation’s technical team moved quickly to diagnose the problem. They identified a specific bug affecting Bor and Erigon nodes that prevented them from advancing properly, essentially stalling the network’s ability to achieve block finality. This is the point at which transactions are considered irreversible.
Despite blocks continuing to be produced, the chain could not reach consensus on their validity.
“We rolled out fixes on both Heimdall (v0.3.1 – a new version with a hardfork to delete the identified milestone) and Bor (2.2.11-beta2 – purging the milestone from the database). With these fixes now live, nodes are not stuck, checkpoints and milestones are finalizing normally,” Sandeep said.
“The team is still monitoring the network closely and is investigating how this scenario occurred in the first place. I’m extremely grateful to our team of engineers for quickly identifying and resolving this issue, and for the patience and understanding of our community,” he added further.
By 3:00 PM UTC the same day, the foundation had developed, tested, and deployed a fix through an emergency hard fork. The update involved releasing new software versions (v0.3.1 for Heimdall and v2.2.11-beta2 for Bor) that resolved the synchronization issue.
Validators and node operators were instructed to restart their systems with the updated software, which quickly restored normal network operation.
This incident shows the latest in a series of significant upgrades for Polygon. Just months earlier, in July 2025, the network underwent its “most technically complex hard fork” since its inception with the Heimdall 2.0 upgrade.
That update introduced a completely new consensus layer and reduced finality times to approximately five seconds. Earlier in the year, the Bhilai hard fork had already boosted network throughput to 1,000 transactions per second.
The market response to the temporary crisis was predictably negative; the token, POL, declined by approximately 4% on the day of the incident, extending its year-to-date losses to over 30%. This performance reflects both the specific network issues and broader challenges in the competitive layer-2 landscape, where Polygon’s total value locked has declined significantly from its 2021 peak of over $9 billion.
The quick resolution demonstrated Polygon’s technical maturity and organizational capability. Unlike the decentralized chaos that sometimes characterizes blockchain crises, the Foundation provided clear communication and direction throughout the incident.
Their proactive monitoring and rapid response prevented what could have become a much more serious outage.
Despite the successful fix, the incident highlighted the ongoing challenges of maintaining complex blockchain infrastructure. Some third-party protocols, like TokenPocket, temporarily halted Polygon transactions to avoid complications, while the network’s block explorer, Polygonscan, showed concerning delays in block updates during the height of the crisis.
The network is already preparing for its next major upgrade, the Rio Hardfork, which will introduce validator-elected block production and advanced verification mechanisms.
These improvements aim to decentralize the network further and enhance its resilience against similar issues in the future.
The episode serves as a reminder that even established blockchain networks face technical challenges, but also demonstrates how experienced teams can respond effectively to maintain network integrity.
As Polygon continues to position itself as critical infrastructure for Ethereum’s scaling, its ability to handle such crises will be crucial to maintaining user and investor confidence in the competitive layer-2 areas.
Rajpalsinh is a crypto journalist with over three years of experience and is currently working with CryptoNewsZ. Throughout his journey, he has honed skills like content optimization and has developed expertise in blockchain platforms, crypto trading bots, and hackathon news and events. He has also written for TheCryptoTimes, where his ability to simplify complex crypto topics makes his articles accessible to a wide audience. Passionate about the ever-evolving crypto space, he stays updated on industry trends to provide well-researched insights. Outside of work, gaming serves as his stress buster, helping him stay focused and refreshed for his next big story. He is always eager to explore new blockchain innovations and their potential impact on the global financial ecosystem.
