Contrary to initial reports here and here, further investigation has revealed that under some specific and limited circumstances, Percona Server and Percona XtraDB Cluster binaries, similar to other MySQL variants, are susceptible to the security vulnerability in MySQL/MariaDB sql/password.c:
The very complicated nature of this issue—the dependency on the software platform, hardware platform, and specific binary—made the security vulnerability difficult to detect and required exhaustive testing. We apologize for any confusion caused by our original post.
As always, we recommend running the latest version of Percona Server, Percona XtraDB Cluster, or any common MySQL variant to minimize security vulnerabilities.