This is the May 2021 release for .NET Core 3.1. Release Notes are here:https://github.com/dotnet/core/blob/main/release-notes/3.1/3.1.15/3.1.15.md
This includes a fix for CVE-2021-31204: NET Core Elevation of Privilege Vulnerability
Please note this additional change needed to benefit from the CVE fix:
Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed.
3.1.15-1.fc323.1.15-1.fc323.1.115-1.fc323.1.15-1.fc323.1.15-1.fc323.1.15-1.fc323.1.15-1.fc323.1.15-1.fc323.1.15-1.fc323.1.15-1.fc32