Details for security updates

I’m helping someone with their security and I’ve noticed they are running an old version of this plugin. I’d like to check their system to determine if there has been any exploitation of the vulnerabilities patched in versions 6.1.2, 6.0.6, 5.3.7, and 5.2.1. The changelog indicates these are security releases, but I don’t see further details. Are there CVE reports for these issue or other tips about detecting exploitation of the patched vulnerabilities?

Thanks!