The current master is now at https://github.com/codehaus-plexus/plexus-archiver
Based on a hint of snyk.io security team they have found a possible security issue. Furthermore they have offered an patch to prevent the possible security issue. This patch has been integrated into the Release 3.6.0
Current release notes are maintained on GitHub releases
You can find details about the historical releases in the Release Notes.