According to the protobuf pypi page 3.12.2 is latest: https://pypi.org/project/protobuf/ It seems on github there's even a 3.12.3 version, but that doesn't seem to be on pypi yet.
I am aware of new releases and I will add 3.12.2. 3.12.3 release was created from wrong branch (branch "master" instead of branch "3.12.x") and will not be added: https://github.com/protocolbuffers/protobuf/issues/7632 https://github.com/protocolbuffers/protobuf/issues/7637
*** Bug 730660 has been marked as a duplicate of this bug. ***
3.12.2 was added.