Gerrit 3.5.6 has been released https://www.gerritcodereview.com/3.5.html#356
Security Fix
Issue 16890 CVE-2019-12402: Fix DoS for Gerrit servers exposing Gitiles with the ability to download source archive
Bump common:compress version to 1.22 for protecting against an infinite loop triggered by downloading a source archive of files with a Unicode filename.
For bug fixes,
Change 362914 Fix internal server error caused by double flush in BaseCommand.TaskThunk
That might solves SshChannelClosedException T263293#8708846
Download-commands plugin fixes
Issue 15944: Update download-commands to latest master
Workarounds Gerrit/jgit not supporting OpenSSH 9 sftp subsystem which is T330740