This minor version is destined for Ghostnet users only. It addresses the issue recently encountered in this network.
Octez v21.2 is required to participate in the Ghostnet network, but has no impact on any other network including Mainnet.
A full changelog and update instructions are available in the version 21 release page.
The Git tag for this release is octez-v21.2
and the corresponding commit hash is 4945ba69
.