On June 5, the Cosmos Hub blockchain network encountered a four-hour outage due to a bug discovered during the implementation of the v17 upgrade.

The Cosmos team identified the bug as a security vulnerability in the Liquid Staking Module (LSM). Developers promptly addressed the issue, but block production resumed only after a majority of validators had applied the patch. The team urged remaining validators to implement the fix, stating:

“Informalinc and HyphaDoesCosmos have issued a fix for the bug. Currently, 55% of validators have implemented the patch. We encourage all remaining validators to do the same.”

Block production resumed around 12:30 A.M. GMT, and the team announced plans to publish a detailed post-mortem report.

Ethan Buchman, Cosmos co-founder, acknowledged that downtime for the Cosmos Hub is rare but inevitable:

“Bugs will occur. Chains may go offline temporarily. The key is having dedicated developers and validators ready to resolve issues as they arise.”

The Cosmos Hub aims to facilitate a network of interconnected blockchains within the Cosmos ecosystem, operating on a proof-of-stake consensus mechanism where participants stake ATOM coins to earn rewards.

Despite the network disruption, the ATOM token remained stable at $8.65, reflecting a 0.67% increase at the time of reporting.

The v17 upgrade was highly anticipated within the Cosmos community, with over 136 million ATOM tokens (99.8% of the total votes) supporting it, according to Mintscan data. This upgrade introduces features from the "partial set security" proposal, enabling new consumer chains to customize validator participation and operational parameters.

Describing it as the largest upgrade in at least a year, Buchman highlighted that v17 includes the long-awaited ICS2.0.