In p7zip-17.03, the function NCompress::CCopyCoder::Code in CPP/7zip/Common/StreamObjects.cpp will call outStream->Write where a memcpy uses a NULL pointer as destination address, leading to a crash.
Created p7zip tracking bugs for this issue:
Affects: fedora-all [bug 1943303]
This seems to be just a crash in a CLI tool, so I don't think it crosses any security boundary or that it has any security impact at all.
Red Hat Product Security does not consider this to be a vulnerability because it is just a crash in a command-line tool which can hardly impact Availability of any well-written service that uses 7z tool.
also we don't use https://github.com/jinfeihan57 fork , at least yet .