The upgrade operation should be a binary replacement without a chain-halt, Please refer to https://github.com/shentufoundation/mainnet/tree/main/shentu-2.2/upgrades#v271-upgrade for upgrade instructions.

Changelog

[v2.7.1] - 05/25/2023

Upgrade IBC to v4.2.1, which addresses a potential security vulnerability impacting IBC connected full nodes.